There are many things you can do to enhance your printer. You can improve the print quality of your printer, improve usability and maintainability, or simply add new features. For example, you may want to improve vertical layer alignment (for smoother surfaces), add an LCD panel for computerless printing, or automated bed leveling (tramming) and Z-axis probing tasks.

Before you do any of these tasks, you should complete a comprehensive set of calibration tasks like those described in Chapter 4. I cannot stress that enough. You really should complete the calibration process before making any changes to your printer. This is because while some upgrades are designed to improve quality (or known to do so), most are not solutions to calibration problems and can make a small problem a larger one.

Now that the requisite admonishments are stated, upgrading a 3D printer can be a great deal of fun. Indeed, it is one of my favorite things to do with 3D printers. I am always looking for a better mount, carriage, or mechanism to improve my printers.

Some of the best platforms for upgrading are the many RepRap variants. Most kits come as bare, essential printers. There are typically no features other than those needed to print. That is, you are not likely to have even simple upgrade features such as fans, lights, or Z-height adjusters. While some kit vendors offer these features as upgrades, most do not include them in the kit.

Enhancements fall into three categories: features that add some minor function (farkles), enhancements to existing features that improve quality (enhancements), and upgrades that add completely new features that improve quality as well as usability, maintainability, and in some cases reliability (upgrades).

In this chapter, I discuss each of these categories, as well as some features generic to all printers, and give examples of upgrades for specific printers. If you own one of these printers or are planning to own one, this chapter will be your road map to taking your printer to new heights.

In some cases, the enhancement can be something that prolongs the usefulness of your printer. For example, I purchased a used MakerBot Replicator 1 Dual, and together with the upgrades, have a printer to rival the newer (and current) MakerBot Replicator 2X. Best of all, the total cost of the printer and the upgrades is less than 50% of the price of the new model. How cool is that? I am certain you can achieve similar goals with careful planning and a good bit of frugality.

Types of Enhancements

I like to break enhancements down into categories based on their function and goals, which indirectly relates to their importance or value for the enthusiasts (what you get out of having the enhancement).

The category of least value for print quality, usability, or maintainability includes enhancements for aesthetics and minor functions. I call this category “farkles,” because they do add some value, but are mostly for show. The next category includes more useful additions because they are targeted or indirectly equate to improving quality. I call these “quality upgrades.” Lastly, anything else that adds a new feature that has some significant improvement for usability, maintainability, or reliability I call simply “feature upgrades.”

The following sections discuss each category in more detail and provide examples. Keep your own printer in mind. It may help you decide what you want to do next with your fully calibrated 3D printer!

Farkles

Recall that a farkle is a borrowed term from motorcycling that is a mash-up of “function” and “sparkle.”¹ We call something a farkle if it has a specific function but is either not essential to the mission of the device on which it is installed, or it adds more glitz and glamor than function. For example, consider a motorcycle festooned with three GPS devices, a compass, multiple cup holders, and more LED lights than a semitractor truck from those trucker movies from the 1980s. Excess is one of the side effects of farkling. However, some farkles are helpful in some way even if they are not essential.

Beautification

One of the most common farkles is an enhancement to the printer frame and enclosure. Some enthusiasts, especially those who have printers with wooden frames, will stain or paint the frame to add some décor to their printer. This often adds only aesthetics and sometimes no functionally to the printer other than your own taste for adventure and personalization. However, it should be note that sealing a wooden frame can protect it from moisture.

In fact, I painted one of the frames (the threaded rods) of one of my Prusa Mendel i2 printers. I painted it black and used black plastic frame components. It looked pretty good, but I must admit it added no functionality whatsoever—unless you consider the effect on the naïve who see the all-black printer and think it is the newest model.

Similarly, some printer vendors allow you to choose the color of your printer either as a factory option or by providing a set of snap- or bolt-on color panels. This also extends to upgrades. As you will see in a later section, you can replace the panels on the MakerBot Replicator 2/2X with colored panels changing the basic black to green, yellow, blue, red, and so forth.

LED Lighting

I added an LED light ring to some of my RepRap printers. I did so because they were being used in some low-light areas of my office and workshop. The LED light allowed me to better see the print and more easily see how well the first layer was adhering to the print surface. So while the LED light ring does provide a useful function, it is mostly for show because there is no need to leave it on while printing. The printer doesn’t need to see where it’s going! Figure 11-1 shows the LED light ring.

It may not be clear in Figure 11-1, but that small ring of LEDs puts out some mighty bright light. Figure 11-2 shows the LED ring on in nearly dark conditions.

This is all well and good and indeed a lot of fun, but most people will want to work on improving the quality of their printer and print experience.

Quality Enhancements

Improvements designed to bolster quality is the category that gets the most attention and offers a seemingly endless array of possibilities. You may immediately associate this (and rightly so) as how well objects are printed. However, there is more to it. I also include in this category the quality of the printer and the quality of the print experience. In other words, not just how well the printer can print, but how effectively it operates and how well you enjoy using it, or even its ease use.

Quality enhancements range from added bracing to help wobbly frames, devices designed to reduce or remove backlash, improved electronics, heating, and so forth. One trip through the Thingiverse search engine for your printer will tell you just how many quality-improvement things are available.

Given its popularity, it should be no surprise that the RepRap variants have countless hits—so many that you have to search for a specific part of the printer to find them all. For example, it is futile to search for “Prusa i2” on Thingiverse. Rather, you should search for what you want to improve. For example, searching with “Prusa i2 filament guide” will list several options to explore for keeping the filament from flopping around and potentially snagging as the extruder pulls it.

Filament Management System

Filament management is one of the largest collections of interesting solutions for printers on Thingiverse. So what is filament management? Recall that one of the potential problems for using your 3D printer is keeping the filament flowing easily so that the extruder isn’t working too hard to pull the filament from the spool, which can cause under extrusion or uneven extrusion if the tension waxes and wanes as the spool turns.² In extreme cases, it can cause the extruder to lift slightly introducing inconsistent layer heights.

What is needed is a system where the spool can turn easily with a small amount of friction (just enough to prevent the spool from unraveling), and one or more guides to keep the filament from snagging on other parts of the printer. Figure 11-3 shows a filament management system that I adopted for all of my Prusa Mendel i2 and similar printers.

Notice the spool is mounted above the extruder and at the rear of the printer. The mount is comprised of five threaded rods, some extra Y-axis bar clamps, and a few extra bits to hold it all together. I also use a filament guide that keeps the filament aligned in the center as it is pulled from the spool. The spool is mounted using two cones that ride on 608zz bearings. Best of all, I made this filament management system from things I found on Thingiverse.

If you’re thinking, “Hey, I can make one of those for my printer!” you’ve got the right idea and it is the right attitude to have to get the most out of your printer. I really enjoy downloading things and printing them—especially if it allows me to improve my printer. You can do the same. Just do a search for “<my printer> filament guide” and “<my printer> spool holder” where <my printer> is the brand or design of your printer (e.g., Prusa i3) and you’ll get plenty of ideas. Chances are you will be able to put one together like I did without having to modify any of the parts!

The parts that I used for this upgrade are all existing designs I found on Thingiverse. There are several similar solutions on Thingiverse and, in fact, one of the parts I used is from a similar design. Table 11-1 lists all of the components should you wish to make your own.

For brevity, I omit the installation procedure but it is not difficult. Just follow the example in Figure 11-3 and read the instructions for each printed object listed in Table 11-1. The longest part of the installation is printing the spool cones.

Insulated Heated Print Bed

Another common quality improvement is insulating the heated print bed. This could be a fix or a cure for some printers that have weaker power supplies or similar power issues where the heated print bed does not remain at a constant temperature. That is, it varies a few degrees as the bed cools (or is cooled by the environment). This fluctuation can cause some quality issues. Insulating the heated print bed can also help printers that take a long time to heat up. In this case, the heaters are losing the battle with the environment to instill enough heat in the bed.

Heated print bed insulation comes in many forms. Some enthusiasts have used materials such as corrugated paper (cardboard), fiberglass, and foam. I have found one of the best materials is from the automotive industry, called exhaust header wrap (or simply exhaust fabric). Figure 11-4 shows an example of this fabric.

Exhaust header insulation is used to wrap headers (the part of the engine where spent gasses are expelled through a collection chamber called the header or manifold). This material has foil on one side and heat resistant insulation on the other. Threads are interwoven at right angles to give the material extra strength. See thermotec.com/products/14001-aluminized-heat-barrier.html for an example of this form of insulation.

Notice that I cut the corner off. I did this for all four corners. This allows me to place the fabric under the heated print bed without interfering with the print bed adjusters. You may have to trim the corners in a similar manner to make it fit around the bed adjusters/mounts. Figure 11-5 shows the fabric cut to size for a Prusa i3.

If your print surface is removable, you can use it to cut the fabric to size by placing the print surface on the fabric and cutting around it. To install the insulation, remove your heated print bed and place the fabric foil-side down on the Y-axis plate. Then put the heated print bed element on top of the fabric and your print surface on top of the heated print bed. Figure 11-6 shows the same fabric mounted on a Prusa Mendel i2.

There are many more such improvements that can help print quality or raise the general quality of your printer and thus your experience. Once you achieve the desired quality, you may want to start considering adding new features to your printer in the form of upgrades.

Feature Upgrades

The last category of improvements includes those that provide a new feature or capability for your printer. Unlike farkles, which add a feature that is not essential (but still usable), features are things that add value to your printer either in quality or through expanding its capability.

For example, adding a camera to the printer would enable you to watch the print from a remote location, or perhaps record the print process as a movie, or even make it available online in real time. Clearly, this is a new capability that can add value in the form of entertainment as well as practicality by allowing you to leave your printer in another room and watch it from, say, the living room.

As we saw in a previous chapter, the list of features for 3D printers is long, and most printers don’t have them all. However, you can add some of these features to your printer to improve it. For example, if your printer did not come with an LCD panel, adding one will enable you to use the printer without a computer. Similarly, if your printer does not have a fine adjuster for the Z-height, you can add one to help make the setup process easier. I describe each of these features in more detail in the following sections.

LCD Panels

The first printers I built and used did not have any form of display. Sure, there were a few LEDs on the electronics and I added a small buzzer for custom signals to one, but that was about it. That is, unless I wanted to add my own feedback mechanisms. I found several ideas using seven-segment displays (think old alarm clock) to show axes positions and voltages, but these would have been a lot of work.

But feedback isn’t really that helpful, given you must have a computer connected to print it, and most printer controller software has the ability to display the current axes positions, temperatures, and more. Even when I added an SD card reader, I still had to use a printer controller application to initiate a print from a file on the SD card.

A display panel will provide much more than simply displaying information about the printer’s status. In fact, most add-on display panels are liquid crystal displays, which we simply call LCD panels. These panels are enabled by the firmware to display feedback, as well as provide a host of printer-side controls from homing axes to setting the hot-end temperature, turning on a fan, and even printing from files on an SD card. Figure 11-7 shows an example of an LCD panel for a Prusa Mendel i2.

The panel shown in Figure 11-7 is a typical text display capable of displaying 4 lines of 20 characters (called a 4×20 display). Notice that there are some special symbols that may appear as graphics, but they are simply special characters programmed in the firmware. The vast majority of LCD panels are text panels.

There are also graphic LCD panels that allow more freedom for implementing more interesting displays.³ There are fewer choices for graphic LCD panels, and most are more expensive. Check your firmware or your vendor before adding a graphic LCD panel. Figure 11-8 shows a graphic LCD panel on a Prusa i3.

As you can see, the display can support up to three extruders, a heated print bed, and a fan. Also displayed are the axes positions and the state of the SD card (% full).

If your printer does not have an LCD panel, check with your vendor to see if they offer an add-on kit. For example, Printrbot has an LCD add-on kit for its line of printers (http://printrbot.com/shop/printrbot-lcd-panel-in-stand/). The kit comes with the panel, a cable, and a stand. Figure 11-9 shows the Printrbot LCD panel.

If you have a RepRap printer, you may be able to use one of several LCD panels—either text or graphic. Look for one that is designed to work with your electronics. For example, if you have a RAMPS setup, choose one that has an adapter made for the RAMPS shield. In order to activate the LCD panel, you will have to modify the firmware by enabling the corresponding #define in the Configuration.h file. Listing 11-1 shows an excerpt of the Marlin firmware, listing the types of panels supported. Just uncomment the one that matches your panel, compile, and upload the firmware.

Listing 11-1. LCD Panel Support in Marlin

...
//LCD and SD support
//#define ULTRA_LCD
//#define DOGLCD
//#define SDSUPPORT
//#define SDSLOW
//#define ENCODER_PULSES_PER_STEP 1
//#define ENCODER_STEPS_PER_MENU_ITEM 5
//#define ULTIMAKERCONTROLLER
//#define ULTIPANEL
//#define LCD_FEEDBACK_FREQUENCY_HZ 1000
//#define LCD_FEEDBACK_FREQUENCY_DURATION_MS 100

// The MaKr3d Makr-Panel with graphic controller and SD support
// http://reprap.org/wiki/MaKr3d_MaKrPanel
//#define MAKRPANEL

// The RepRapDiscount Smart Controller (white PCB)
// http://reprap.org/wiki/RepRapDiscount_Smart_Controller
//#define REPRAP_DISCOUNT_SMART_CONTROLLER

// The GADGETS3D G3D LCD/SD Controller (blue PCB)
// http://reprap.org/wiki/RAMPS_1.3/1.4_GADGETS3D_Shield_with_Panel
//#define G3D_PANEL

// The RepRapDiscount FULL GRAPHIC Smart Controller (quadratic white PCB)
// http://reprap.org/wiki/RepRapDiscount_Full_Graphic_Smart_Controller
//
// ==> REMEMBER TO INSTALL U8glib to your ARDUINO library folder: 
http://code.google.com/p/u8glib/wiki/u8glib
//#define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
...

More recent printers are being shipped with LCD panels as a standard feature. For example, all except one of the newest MakerBot printers have LCD panels. The newest MakerBot Replicator Desktop has a graphic LCD panel.

Z-Height Adjuster

If your printer came with fixed endstops like most RepRap printers, and you did not add any adjusters to the print bed, then you have likely encountered some frustration in printing. Unless your printer is calibrated well and is not affected by changes in your environment, there is little chance you’ve been spared the frustration.

What I am referring to is the problem of setting the Z-height or the initial layer height of the nozzle above the print surface. Recall that this distance is critical for good adhesion to the print surface and indeed forms the foundation for good quality prints. Figure 11-10 shows one example that I’ve found works very well (see thingiverse.com/thing:16380).

The endstop is indicated with a square box. Notice that it is mounted on an arm that has a knob and is under tension. The knob turns a bolt that is threaded through a nylock nut. This gives the ability to adjust the endstop up or down in very small increments.

Those who have faced this problem typically have to move fixed endstops by loosening one or more clamps, sliding the endstop one way or the other, and then testing the height of the nozzle. But there is a better way. You can install a Z-height adjuster that mounts the Z-axis endstop on a fine adjuster mechanism.

Does this sound like bed leveling? That’s because this process is one of the steps, but in the case of bed leveling, we are tramming the print bed with the X and Y axes. The Z-height is part of the equation, but what if your print bed is already leveled (trammed)? How do you set the Z-height—do you adjust each of the bed adjusters? That’s too much work. Wouldn’t it be better to adjust only the Z-axis endstop?

Perhaps a better question might be why you might need to set the Z-height. It’s quite simple and yet rather unintuitive. Depending on the material you are printing with and the condition and type of print surface, you may need a lower Z-height to help with adhesion. I would recommend using the highest setting possible that still permits good adhesion, but sometimes you just need to squish that filament to make it stick (and avoid lifting).

Another and perhaps obscure use for the Z-height adjuster is for printers that have an uneven print surface. If the print surface is too uneven, you will never get a good print; but if it is slightly concave or convex (which is not uncommon for hardware store–quality glass), leveling the bed at the corners leaves the area in the center too low or too high for good prints. Having the Z-height adjuster allows me to position the nozzle in the center of where I want to print and set the Z-height for that area. Of course, the real fix is to throw the bad glass away and get a flat piece. However, if you don’t have that option because the surface isn’t glass or is very expensive, the Z-height adjuster can help.

If you search Thingiverse, you will find many examples of Z-height adjusters. Just search for “z-height <printer_name>” and you should find plenty of alternatives. Indeed, you should find a number of different mechanisms. Look for the one that is mounted in a position that is favorable to your printer design. For example, there are a lot of examples of Z-height adjusters for RepRap printers, but some are specific to certain variants and some may conflict with other upgrades you might have installed. However, given that the parts are generally small and don’t take long to print, you can download and print several, and then choose the one you like best.

Upgrading Your Printer: Getting Started

I hope that you are excited about the many possibilities and ideas for upgrading your printer. I know I’ve really enjoyed working on my printers and making them (in some cases far) better. However, you should probably hold off downloading and printing a bunch of parts, or ordering any expensive machined parts, until you figure out what you want to achieve and how to get there. In other words, you need a plan.⁴

Failure to do this could lead to less-than-expected results, wasted time and money, and a great deal more frustration than you ever wanted. For example, resist the temptation to buy the latest and greatest hot end on the market until someone has reviewed it or at least used it for some time. If you fall into this temptation, you could end up with a very nice looking knickknack shaped like a hot end. Yep, I’ve got one. I suppose several of us do.

Do Your Research: Finding Upgrades

In the previous sections, I mentioned searching Thingiverse for ideas and objects that you can use to effect upgrades and enhancements to your printer. Depending on how long your printer design has been used, you should be able to find solutions that other enthusiasts have created. I recommend starting with those before attempting to develop your own. It will save you a lot of time (and frustration) and could give you ideas for improvements to the design that you can create and also publish for others to use.

The best way to search for upgrades and enhancements is to use search terms that include the name of your printer design (e.g., Prusa i3, Printrbot Simple, MakerBot Replicator, etc.). I would start here as the first search. Chances are you will get a lot of results. If you are not sure what sort of upgrade you’re looking for, this may be the best way to find what is available.

On the other hand, if you know what upgrade you are looking for, add it to the search term with the name of your printer design. It is better to use short search terms than long descriptions. That is, to widen your search results, omit as many words as you can. For example, if you are looking for adjustable feet for your Prusa i3, search “Prusa i3 feet”.

If you do not find what you are looking for, you can try different search terms. For example, use “Prusa i3 adjuster” if you don’t find any hits from using “Prusa i3 feet”. I find myself doing several searches and examining the results of each. Sometimes things are named oddly and may not appear in some searches.

Once you find the thing you want to use, check the object page and read all of the information. Pay particular attention to the instructions and any installation tips or requirements for hardware. I typically avoid using things that have little or no information—especially if they are complex, multipart things. For example, I once found a nifty dual extruder for a Prusa i3, but it was made from at least a dozen parts, there were no instructions, and no parts list. Don’t make your experience worse by trying to figure out someone else’s half-baked idea.

In a previous section I described a filament management system that I mashed together from several spare parts and a small handful of objects that I downloaded from Thingiverse. Before you use any object you find online, be sure to check the license associated with the object to make sure that you are permitted to use it. Fortunately, most things on Thingiverse have few restrictions.

Set Your Goals and Expectations

Once you find an upgrade (or several) that you want to perform on your printer, you need to set your goals and expectations. You should have a clear idea for what you want to upgrade and why. Unless the upgrade is a farkle, you should understand how the upgrade should affect your printer. With this knowledge, you should also be able to set your expectations accordingly.

This applies most appropriately to upgrades found online. Prepackaged upgrade kits from vendors are typically well-sorted out and should work as expected, but things created by the community may or may not be so reliable (but many are). What you do not want to do is find some gee-whiz upgrade, download and print it, and then install it—only to discover it doesn’t work or makes your printer worse, or even makes it unusable.

Thus, you should research the upgrade carefully. Pay particular attention to other people who have commented on the upgrade. One indication of the quality or applicability of the upgrade is the number of times it has been downloaded and printed.

Once you have this information, compile it so that you understand what the upgrade will do for you. If the upgrade is designed to improve quality, try to determine how much it will improve quality. I recommend tempering your expectations and avoid the trap of thinking an upgrade will solve all of your problems. Simply put, very few upgrades will fall into this category.

Check Your Calibration

Once you perform an upgrade, always check your printer for proper calibration. Most times this is simply making sure things are still aligned like they are supposed to be. For example, if you have to partially disassemble the frame to install some upgrade, make sure the frame is square and true during reassembly.

Similarly, print at least one test print of an easy object and another of a more difficult object before declaring victory. During the upgrade, sometimes minor and not clearly visible changes can be incurred that affect print quality. These may not have anything to do with the upgrade itself even, but may inadvertently change something enough to cause a problem.

For example, when I installed a Z-height adjuster on my first Prusa i3, I inadvertently repositioned the endstop holder for the Z axis. The first time I homed the printer, the Z axis didn’t stop because the plunger I used for the endstop missed the endstop arm by less than a millimeter—but enough to cause the print head to run into the print bed. No, I was not happy. Fortunately, the mistake was minor and I powered the printer off quickly enough to avoid damage to my print surface and axes components.

One Upgrade at a Time

You should resist the temptation to perform multiple upgrades at the same time. This is one way you can make your life much more difficult than it already is. More specifically, if you attempt to upgrade multiple parts of your printer and something goes wrong—or worse, needs recalibration—how do you know which upgrade introduced the problem or even what calibrations need revisiting?

Thus, you should always stick to one upgrade at a time, perfect the installation and calibration, and use the printer for several prints of various difficulty and length before moving on to the next upgrade.

Generic Upgrades: Your First Upgrade

So you’ve decided to upgrade your printer. That’s great! Now, where do you start? I recommend starting small with some simple upgrades that will give you a degree of fun and satisfaction without risking your printer’s quality. As such, I will describe some upgrades that apply to almost all printer designs. The following list includes the goals of some generic upgrades that are good choices for a first upgrade. I discuss each in more detail next.

• Lighting: Making it easier to see your prints
• Fans: Cooling for PLA printing, cooling electronics
• Adjustable feet: Stability for uneven (or tilted) work surfaces

Lighting

I described an LED light ring that I added to my Prusa Mendel i2 printers. This ring illuminated the area below and around the nozzle, which makes it easier to see the print and helps determine if there are problems with adhesion.

If you want to use my LED light ring solution, all you need is a 12V 60mm LED light ring (the same used in automotive lights) and a mount for the ring. There are several options available on Thingiverse. My solution is a special standoff for the X-carriage (thingiverse.com/thing:219419). You can download the .scad file and change it to match your own X-carriage.

You could do something similar and simpler by mounting LEDs to the frame and wiring them to the power supply or via a switch. I recommend searching Thingiverse for LED mounts and switch mounts for your printer. Like most upgrades, you will find a lot of examples.

There are other forms of lighting you may want to consider. For instance, MakerBot printers use LED area lighting to illuminate the build area. Although the LEDs are not bright enough to illuminate the build area (unless it is really dark), it does provide function beyond the mood lighting—a visual cue in the form of changing the LED color to red when the extruder is heating. You could do something similar, but it would require modifying the firmware. Thus, this may be a job for more experienced enthusiasts.

The best part of adding lighting to your printer is it won’t affect your printer’s capability. You can add the lighting, try it out, change it, and repeat as many times as you want with little risk.

Adjustable Feet

If your workstation or the desk surface where you place your printer is uneven, you may want to consider adding a set of adjustable feet. You’ve seen these before on furniture and appliances. They are composed of a threaded rod and nut that rides on a wide disc that makes contact with the surface (floor). If you turn the adjuster, you can raise or lower it, and therefore balance the device. You can also use the adjusters to make the device level (not the same as bed leveling and not required for such). Figure 11-11 shows a set of adjustable feet that I made for my MakerBot Replicator 2. You can find these on Thingiverse (thingiverse.com/thing:232984).

These are great additions because they print quickly, can be modified to fit almost any bolt and nut you have in your spares list (I used some leftover feet from an Ikea purchase), and they don’t impede your printer’s capabilities. Simply print out four of the mounts, remove the stock feet, thread in your adjusters, and install them. You can finally remove that folded piece of paper from under the one corner to keep the bot from rocking.

Fans

Recall that fans are used to cool components (electronics, stepper motors, etc.) and to cool filament as it exits the extruder, and even to cool the part during printing to keep the temperature even and avoid lifting and cracking. Most printers, especially printer kits, do not come with fans to cool the electronics. However, most that are advertised to print with PLA come with print cooling fans. If your printer has neither of these, you can add them.

Fortunately, there are many options available on Thingiverse for fan mounts, including mounts for electronics and extruders. Figure 11-12 shows a fan mounted on a Prusa Mendel i2. This is composed of a 40mm fan purchased online, a mount for the X-carriage I modified, and a cone to direct the air (thingiverse.com/thing:26650).

Installation of the print cooling fan will depend on the mount and cone you use. Notice that in Figure 11-12 the cone fits just under my LED light ring. Had I used a different cone, it would not have fit. Be sure to test fit your parts as you assemble. Fortunately, the mounts and cones print rather quickly, so you can print another if you need to. To connect the fan, you should wire it into your electronics setup. You could wire it directly to the appropriate PSU lead (12v), but you would have to turn it on and off manually (via a switch). However, there is a better way.

Most electronics boards have a connector for a print cooling fan. In fact, the RAMPS shield has terminals that allow you to wire the fan. This is really important because unlike a fan that runs at full speed, the firmware can set the fan speed automatically based on the codes in the print file. More specifically, you can turn on automatic cooling in your slicer that will control how fast the fan spins, depending on the progress of the print. This allows the slicer to use the fan to optimize the print automatically.

So if you are printing with PLA and don’t have a fan, do yourself a great favor and download a mount for your printer, and a cone to direct the air. Buy a fan, and then mount it and wire it into your RAMPS board. You won’t regret this upgrade and it demonstrates how some upgrades add features that go beyond minor improvements in quality. In this case, the fan can make your potentially miserable PLA printing experience much better.

Which One Should I Choose?

The first two generic upgrades are functional in the sense that they improve the printer but are really farkles. If your printer was sitting on an uneven surface, the adjustable feet may be less of a farkle, but essentially they add a feature that doesn’t immediately improve printing. The last generic upgrade, on the other hand, isn’t a farkle because it adds to the printer’s reliability in the very least, and functionality in the case of a fan for printing with PLA.

If you are looking for an easy project to start with, go with the adjustable feet. Even if your printer is an older Prusa Mendel i2, you will find several solutions and the task will be rewarding. If you want a bit more of a challenge and don’t mind working with the wiring of your printer, go with the lighting option. If you would rather upgrade the functionality of your printer—especially if you are trying to print PLA without  a fan, print yourself a fan mount and wire up the fan.

Whichever upgrade you decide to start with (or maybe all of them), make sure you follow the preceding advice for planning, implementing, and testing the upgrade. If you are ready to move on to adding other upgrades and features, the next sections will provide you some ideas for upgrades for a series of popular 3D printer models. I haven’t listed all possible models or vendors here, but seeing these should give you ideas on how to apply similar upgrades to your printer.

Printer-Specific Upgrades

This section includes examples of common 3D printers that have been heavily modified. Most of the hardware for the upgrades is available worldwide, and some include parts that you can print yourself. I recommend reading through each of these sections because some of the upgrades are repeated. Seeing them applied to different printers will give you an idea of how to upgrade your own printer should you not own one of these. The following printers are included in this section. I offer a short description of the end result of the upgrades.

• Printrbot Simple: Improvements to X and Y axes, Z-probing, and LCD panel make this entry-level printer a mid-range printer
• Prusa Mendel i2: Numerous upgrades from farkles to feature upgrades take the i2 to its max
• Prusa i3: Several key improvements, including Z-probing, improve on the latest Prusa design
• MakerBot Replicator 1 Dual: Making an old design new again
• MakerBot Replicator 2/2X: Ultimate upgrade path for MakerBot enthusiasts

Printrbot Simple

The Printrbot Simple is an excellent first printer. Whether you buy the kit or a preassembled printer, the Printrbot Simple is all you need to get into the 3D printing world. Given its price point, you won’t find advanced features, such as an LCD panel or a heated print bed; these would add significantly to the price. Printrbot has also simplified many of the components in an effort to further minimize cost. So much so that some of the parts from older Simples can be a bit finicky to set up and keep working well. For example, one of the limitations and a source of criticism for older models is the string-drive for the X and Y axes.

However, you can improve these features and even add some of the features found on more expensive printers. The following is a list of the upgrades that I have made to my own Printrbot Simple. I include the source for each upgrade. See if you can spot the upgrades in Figure 11-13. I encourage you to explore the links for each of these to see if the upgrade is something you want to perform on your printer. I discuss those upgrades I feel are a must-have for this printer design in more detail in the following sections.

• LCD panel: http://printrbot.com/shop/printrbot-lcd-panel-in-stand/
• Onboard LCD mount:⁵ thingiverse.com/thing:193955
• Metal Extruder and print bed: http://printrbot.com/shop/printrbot-alu-extruder/
• X-axis belt drive: thingiverse.com/thing:194686
• Y-axis belt drive: thingiverse.com/thing:194586
• Z-probe (auto leveling): http://printrbot.com/shop/auto-leveling-probe-2/
• Z-probe mount: thingiverse.com/thing:323442
• Tower kit with spool holder:  http://printrbot.com/shop/printrbot-simple-xl-upgrade-kit/
• Power supply upgrade: thingiverse.com/thing:383877

If you implement all of these upgrades, you will turn your entry-level printer into a mid-level printer. It still may not compete with the more sophisticated (and expensive) models, but it will hold its own feature-wise. Thus, if you find you want a bit more from your Printrbot Simple, check out these upgrades. Figure 11-13 shows my heavily upgraded Printrbot Simple.

Belt Drive Upgrades

Aside from the LCD panel, the string and sanding wheel drive for the X and Y axes are the next parts you should upgrade. The main reason for the upgrade is the string can sometimes be finicky to keep tensioned. If you tighten it too much, it can stretch. Too loose, and you have axis movement issues that can affect quality. Perhaps most of all, I found I needed to tighten the string about every three or four prints (even with small prints).

How you upgrade the X and Y axis will depend on what model Printrbot Simple you have. Printrbot has made numerous changes to the Simple over a relatively short period. Currently, the wooden frame Simples are becoming legacy (think last year’s model). If you have a Simple made before about February 2014, you can download and print axes upgrade parts from Thingiverse (see thingiverse.com/thing:194686 for the X axis and thingiverse.com/thing:194586 for the Y axis). These are the upgrades shown in Figure 11-13. If you have a newer Printrbot Simple, you can use a special upgrade kit from Printrbot (http://printrbot.com/shop/makers-upgrade-kit/).

Whichever belt drive upgrade you choose, you should consider doing this upgrade only after you have calibrated the printer and have established a stable print quality. I discuss installation specifics in the following sections.

Older Simple Printers

The upgrades available on Thingiverse can be applied to a number of older Simple designs. While the installation is a little tedious, requiring partial disassembly, most enthusiasts should be able to perform the upgrade. If you are new to building 3D printers, you may want to study the documents on Thingiverse before installing, so that you know what you are getting into. I will describe the process here, but the finer details are found in the supplied documents.

The only parts you need to buy for these upgrades are a pair of GT2 16-tooth drive pulleys (they have teeth like a gear) and a length of GT2 belt. I recommend finding a GT2 belt and pulley kit from a RepRap supplier. The cost should be reasonable and you will get everything you need. You will also need (four) 608zz bearings. Again, you can find these at popular RepRap suppliers. The only other things you might need include a few zip ties and a few M3 bolts. Check Thingiverse for specifics on what bolts you need.

You can print most of the parts in these upgrades. For the X axis, you will print five parts; and for the Y axis, you will print 6 parts. Printing the parts for the upgrade will take a couple of hours if you use your Printrbot Simple, but it will be well worth the effort.

Once all of the parts are printed, it’s time to install them. Installation for the Y axis is pretty straightforward. You simply remove the existing string and sanding wheel, cut the zip ties holding the Y axis, remove the bolts for the Y-axis motor, and install the new pulley drive. Check the supplied drawings for the proper orientation. Next, you install the pulley and then reassemble the Y axis. Finally, install the bearings, thread the belt, and secure it on each end as directed. The connection on the rear will double as a tensioner. The only issue you may have is the need to trim the opening for the pulley, but I did not have to do that for my Simple (manufactured in January 2014).

Installation of the X axis is a bit more problematic because you have to disassemble about 50% of the printer frame to get the new parts in place. That is, the X-axis motor mount must be replaced. This will require removing all of the panels on the base of the printer. If you are careful and don’t tilt the printer too much, you should not lose any nuts from the nut traps. If some fall out, be patient and use blue painter’s tape to keep them in place while you thread the bolts.

The last step requires recalibrating the X and Y axes steps per millimeter. Fortunately, you can effect this change without reflashing the firmware. First, use the M503 command to read the existing configuration. Look for the M92 entry in the list and note the values. You need only change the ones for the X and Y axes. Next, issue the M92 command with the new parameters, and then use M500 to write the changes to memory. You can then use the M501 command to see the changes. Listing 11-2 shows a transcript of the commands. I omit some of the output for brevity.

Listing 11-2. Setting the Steps per Millimeter

< 8:34:42 PM: echo:Steps per unit:
< 8:34:42 PM: echo:  M92 X84.40 Y84.40 Z2020.00 E96.00
...
< 8:36:47 PM: echo:Settings Stored
< 8:36:49 PM: echo:Stored settings retrieved
< 8:36:49 PM: echo:Steps per unit:
< 8:36:49 PM: echo:  M92 X80.00 Y80.00 Z2020.00 E96.00
...

Notice that the original values for the X and Y axes are 84.40 and 84.40. If you use the 16-tooth GT2 pulleys, you need to change this to 80.00 for each, as I have done in Listing 11-2. Recall that we can calculate this using the Prusa online calculator (http://calculator.josefprusa.cz/). Use the calculator to calculate the correct value if you use a different pulley.

Overall, this upgrade is a nontrivial installation. However, you should be able to complete the installation for each axis in about an hour or two if you take your time.

Newer Simple Printers

If you have a newer Printrbot Simple, you can buy Printrbot’s belt-driven upgrade. The Maker’s Upgrade Kit comes with almost a completely new frame. This is a special design that accommodates the changes to the X and Y axis. Aside from the pulleys, bearings, and belts, the kit also includes a larger stepper motor for the Y axis.

Since most of the frame components are new, installation requires a nearly complete teardown of the frame. Thus, the installation could take an afternoon or more to complete. There is so much work that I would recommend that those who haven’t built their Simple printer to carefully consider the installation instructions before attempting the upgrade.

Like the previous upgrade option, you must reset the steps per millimeter for the axes. You can use the same commands as shown in Listing 11-2.

LCD Panel and Onboard Mount

It’s hard to deny the convenience of having the ability to use your 3D printer without a computer. The lack of an LCD panel is one thing that might keep enthusiasts new to 3D printers from buying the Printrbot Simple. Fortunately, that is very easy to remedy.

Printrbot offers an LCD upgrade for a reasonable price (http://printrbot.com/shop/printrbot-lcd-panel-in-stand/). The kit comes unassembled, but assembly is not difficult and shouldn’t take more than a few minutes. It includes an LCD panel and remote stand (but no SD card reader like those for RepRap printers).

Once the stand is assembled, all you need to do is power-off your printer and plug in the included ribbon cable. When you next power-on the printer, you will be rewarded with a nifty display that you can use to access various menus to manipulate the printer. Another nifty feature is the stand, which can be moved around because it is tethered to the printer via the ribbon cable and not mounted to the frame.

However, if you do not like that (I didn’t), and you have the tower upgrade, you can print a different stand that clips to the handle portion of the tower upgrade. The new stand requires printing three parts that reuse the existing hardware from the LCD kit (see thingiverse.com/thing:193955 for details on how to print and assemble the stand). You can see the stand in action in Figure 11-13.

Z-Probe and Mount (Auto Bed Leveling)

One of the hottest upgrades for 3D printers is called auto bed leveling.⁶ Printrbot offers an upgrade to add this feature to its printers. It is a special probe that uses an induction sensor mounted to the Z axis. The sensor requires you have the metal print bed upgrade. Thus, in order to implement this upgrade, you must first upgrade the print bed.

Installation of the Z-probe requires mounting the Z-probe to the extruder mount using one of several options. Look on Thingiverse for a mount specific to your Simple printer. Mine is an early 2014 model and the mount (thingiverse.com/thing:323442) works well. It mounts the Z-probe to the left of the extruder. Installation was very easy and required only removing the bolts for the extruder to install the mount. Figure 11-13 shows the Z-probe installed on my Printrbot Simple.

Be sure to download and follow the instructions on the product web site. Read all instructions before starting. Printrbot has created a fantastic video that shows the calibration steps (http://youtu.be/lgVmNuwMH68). I recommend watching this video in addition to reading the following procedure.

To wire the probe, route the wires to replace the existing Z-axis endstop. To calibrate the Z-probe, power-on the printer and lower the Z axis until the tip of the nozzle just touches the print surface. Then adjust the Z-probe until it is triggered. You can tell it is triggered when the LED on top of the probe illuminates.

The next step requires loading the latest firmware from Printrbot. But first, check the location of your Y-axis endstop. If it is mounted on the front of the chassis, the latest firmware can be downloaded and installed on your Simple without modification. Check the Z-probe product web site for links to the latest firmware. If you are using a Mac, you can download an automatic firmware updater application from printrbottalk.com/wiki/index.php?title=User:PxT.

If your Simple has the Y-axis endstop at the rear of the chassis, things get a little more problematic. You must download the latest Printrbot fork of the Marlin firmware, modify the configuration source file, and compile it. You will need the Arduino IDE and a special library to allow you to compile the firmware for the Printrboard.

If you have a Mac, you can use the prebundled Arduino IDE at printrbottalk.com/wiki/index.php?title=User:PxT. The instructions for modifying the Arduino IDE for other platforms can be found at http://reprap.org/wiki/Printrboard (see the bootloader section).

Additional instructions for downloading, compiling, and loading the firmware can be found at http://printrbot.com/wp-content/uploads/2012/04/Printrbot-Firmware.pdf. I recommend downloading and reading this document in addition to the overview here.

If your Y axis endstop is mounted at the rear of the chassis, the firmware must be changed. This is because the latest firmware is set up to home the Y axis at the maximum position (the endstop is at the maximum position on the Y axis). Older Simples home to the minimum position for the Y axis.

Before you install the new firmware, issue the M503 command via a printer controller application and copy and paste the information shown. You want to capture the values for the M92 command. You will need to set these values and save them to memory after the firmware is loaded.⁷

For some, this may sound like a lot of work and maybe a bit more than they want to go through for this particular upgrade. However, the modifications are not onerous. You need to change only one line in the Configuration.h file. Look for the following line and change it as shown here. You can find the Marlin firmware at https://github.com/PxT/Marlin/tree/leading-edge. Click the Download Zip button to download the firmware source code.

#define Y_HOME_DIR -1

Once the code has been changed and compiled, you can then upload the firmware to the printer. Follow the instructions in the preceding links for your specific platform. Essentially, you will need to place a jumper on the Printrboard, power the printer on, and then copy the .hex file (shown at the end of the compilation results) to the bootloader application and follow the instructions. You can then power-off the printer, remove the jumper, and power it back on.

Finally, you can issue the M92, M500, and M501 commands to set the parameters for your printer. This is the same process for the X- and Y-axis upgrade. See Listing 11-2. Note that you can set these values in the firmware if you choose, but it is easier to set them via a printer controller application.

You also need to set the offset for the Z-probe with the M212 command. In this case, you will need to know how far away the probe is from the nozzle. If mounted on the left of the extruder, use a value of 0 for the X axis and measure how far away the probe is in the Y direction. If the probe is behind the nozzle and toward the rear of the platform, use a positive value. If it is in front of the nozzle and toward front of the platform, use a negative value. For the Z axis, it will take some trial and error. Start with a value of –0.9 and adjust as needed.

For example, the probe shown in Figure 11-13 is mounted to the left of the extruder and 10mm away from the nozzle in the Y direction. I used the following command to set the values, saved them to memory, and read them to verify the settings.

M212 X0 Y10 Z-0.9
M500
M501

To use the new feature, you must change your slicer to home the X and Y axes, and then issue the new bed-leveling command. Open your slicer and locate the custom preprint G-code settings and change them as follows. These commands home the X and Y axes, and then take three Z-probe readings and calculate the bed offset based on those points. This compensates for an unleveled (untrammed) bed.

G28 X0 Y0
G29

Now comes the really fun part. Use your printer controller application to print a small object using the new G-code commands. Keep your hand on the power supply and be ready to pull the cord. Watch the printer carefully. If the nozzle looks like it is going to dig into the print bed, pull the plug and set the Z axis value for the M212 command to a lower value. If the nozzle strikes the print bed, set it to –2.0 and try the print again.

Once you establish a setting where the nozzle is not striking the print bed, repeat the M212 command, adding 0.2 to the value until you get a good first layer adhesion. Repeat these steps until you get a good print. Don’t forget to write the values to memory each time with the M500 command. If you get close, you can use a value of 0.1 to fine-tune the position.

If this sounds like a bit of trial and error—you’re right, it is. When you reach the point where the Z-probe Z-axis offset is dialed in and your first layer is adhered well, you’re all set! Don’t forget to reslice your objects to take advantage of the new preprint g-codes.

Power Supply

The power supply included with the Printrbot Simple is a bit fragile. I am not certain how high the failure rate is for the power supply, but it is clear a fair number of them have failed. If you are one of the unfortunate to experience a dead Printrbot Simple power supply, and you have had your printer longer than the warranty coverage, you’re facing a pretty expensive replacement if you buy it from Printrbot.

There is an alternative—make your own! When mine failed, I contacted Printrbot technical support for their recommendation for a replacement power supply. Printrbot said a 12v/20a power supply would be more than adequate (and perhaps the max) for the Printrbot Simple.

I created a set of covers for a typical 12v/20a LED power supply and uploaded them to Thingiverse (thingiverse.com/thing:383877). These power supplies are very plentiful and can be found on most online electronics stores, auctions sites, and even Amazon.com. Figure 11-14 shows the completed power supply.

Other Considerations

I did not list a heated print bed for this printer, but it is possible to add a heated print bed. In fact, if you have the metal bed upgrade (or the all-metal Printrbot Simple; see the upcoming sidebar), there are holes for mounting a heated print bed. The reason I did not list a heated print bed as a must-have upgrade is because it really isn’t needed, given the small build volume and onboard fan. I think most people will use PLA exclusively, and even without a heated print bed, the Printrbot delivers very good quality with little lifting.

If you want to add a heated print bed to your Printrbot Simple, you will also need the upgraded power supply because the stock power supply is not adequate for powering a heater. If you upgrade the power supply like I described, you will have enough power to run the heated print bed.

However, there is a trick. You will need to wire a relay in between the Printrboard and the heated print bed. This will allow the Printrboard to trigger power to the heater without drawing power from the board. Some people have success wiring the heated print bed through the Printrboard, but I recommend the use of a relay or perhaps a MOSFET just to be safe. You may also need to change the firmware to limit the switching rate. If you are interested in this upgrade, be sure to Google for solutions and examples.

Another consideration is a good spool holder. It is not essential to get the tower kit I listed earlier, but you should have some form of spool holder to keep the filament feeding smoothly. Check out Thingiverse for a host of spool holders.

Prusa Mendel i2

The Prusa Mendel i2 printer is a great choice for those who want to dive into the RepRap world of open source 3D printers—especially so for anyone seeking to build their own printer. Since this RepRap variant is a few years old, parts are plentiful and kits can be purchased from many vendors.

The platform is also an excellent choice for those who want to make a hobby out of experimenting with upgrades and new technologies for 3D printers. That is, anyone who likes to tinker with augmenting and improving things. I suppose you can toss me into this category because a number of my printers are manifestations of my desire to tinker and improve on existing designs.

One of the downsides to choosing the Prusa Mendel i2 kit is that most kits are bare bones in the sense that they include only those features that you must have to print. Like the Printrbot Simple, there are rarely features like LCD panels, Z-height adjusters, or even adjustable endstops. Some kits don’t even come with power supplies or glass for the print bed. However, most do include a heated print bed. What this means is if you buy a kit for this platform, you will probably want to upgrade it soon after you build it.

Fortunately, since the Prusa Mendel i2 has been around a few years, there are hundreds of modifications available with a vast array of designs. Perhaps best of all, most of the latest upgrades are available for this platform. If you search online or on Thingiverse, you will find upgrades ranging from variations on a theme (e.g., Z-axis improvements), new features (e.g., auto bed leveling), and even a number of common upgrades (e.g., LCD panels).

In fact, almost all of the upgrades I’ve made to my Prusa Mendel i2 printers have been sourced from Thingiverse and online retailers who sell RepRap components. The following lists numerous upgrades and improvements I have made to one of my Prusa Mendel i2 printers. I will discuss those upgrades I feel are a must-have for any Prusa Mendel i2 owner in the following sections. Figure 11-15 shows what my printer looks like today with all of these upgrades installed. See if you can find the upgrades in the photo.

• Adjustable feet: thingiverse.com/thing:249932.
• Print bed adjusters: thingiverse.com/thing:16428.
• Borosilicate glass print surface: Various online retailers.
• Insulated print bed: Various online retailers.
• Z-axis fix: Replace 608zz bearing with a thrust bearing of the same outer dimensions.
• Switch mount for accessories: thingiverse.com/thing:381392.
• RAMPS fan: thingiverse.com/thing:30331.
• Power terminal: Various online retailers. Clamps are common endstop mounts.
• LCD panel: Various online retailers. Mount is from thingiverse.com/thing:84535.
• RAMPS mount: thingiverse.com/thing:17912.
• Power inlet mount and switch: thingiverse.com/thing:26105.
• Upgraded Y-axis belt clamps: thingiverse.com/thing:91370.
• Onboard power supply mount: thingiverse.com/thing:57520.
• Z-height adjuster: thingiverse.com/thing:16380.
• Print cooling fan: thingiverse.com/thing:26650.
• LED light ring: Auto parts stores, thingiverse.com/thing:219419.
• Spool holder and filament guide: (See the preceding details).
• Y-axis belt tensioner: thingiverse.com/thing:74209.
• Filament cleaner: thingiverse.com/thing:16483.

If you’re thinking that is a lot of upgrades, you’re right, and they’re all on the printer. It isn’t my most upgraded printer, but it is close. There are also numerous small tweaks of less significance.

The following sections list those upgrades I feel are essential and must-have to make the Prusa Mendel i2 a very good, stable 3D printing platform. While I consider each one to be a must-have item, I list them in the order of ease of installation. You can use this as a roadmap for your own upgrades. I have discussed some of these previously, but I include them here for anyone looking to improve their Prusa Mendel i2.

LCD Panel

I have discussed the LCD panel and its many virtues and conveniences. Recall that an LCD panel makes it possible to use your printer without the need for a computer. Most also give you the ability to print from an SD card. Figure 11-16 shows an LCD panel mounted on the top-right portion of the frame in front of the right-side Z-axis motor. I find this location very well-suited for right-handed use. Mount it on the left if you prefer left-handed use.⁸

Borosilicate Glass Print Surface

One of the easiest upgrades you will ever do is replacing your print surface with higher-quality glass. I have found that Borosilicate glass makes an excellent print surface that transfers heat well, and more importantly, is very flat.

Some enthusiasts have used mirrored glass for their print bed with great success. Again, the key is how flat the surface is. If you want to use mirrored glass, check it carefully for distortions. Only one side of the mirrored glass needs to be perfectly flat—the side without the reflective coating (the top side). Don’t be lured into thinking all mirrored glass is flat. Furthermore, I am not so certain the reflective coating can withstand numerous heating and cooling cycles.

Like most other enthusiasts, I used hardware store-grade plate glass for my build surface. But this glass is seldom flat enough for use with 3D printers. There is always some unevenness. That is, the glass has some small amount of wave or bend in it. I found one case where the center was nearly 0.05mm lower than the four corners. Turned over it was nearly 0.08mm higher, so thickness was a problem too.

Distortions like this in the glass can cause bed leveling problems, make Z-height adjustment a nightmare, and cause lifting and poor-quality parts. The only way to discover defects is to use a dial gauge mounted on your X axis to take measurements at the four corners, center, and other points. A good print surface should have no more than about 0.01mm to 0.02mm variance from one spot to the next.

If you are using lower-grade glass for your print bed, you should consider getting a Borosilicate glass plate. You can find these at some 3D printer online vendors and also on popular online auction sites. Be sure to find one sized for your print bed, because it cannot be easily cut to fit. Installation is simple and easy—just remove the old glass and put the new one in place. Just let that puppy cool first if you’ve been printing lately!

Spool Holder and Filament Guide

I presented a filament management system in great detail in the “Filament Management System”  section. I think every printer should have a similar system installed either onboard, like I have built, or as a remote spool holder. Recall that the objective is to reduce the friction on the filament so that it does not cause the extruder to pull the filament unevenly. That is, if the spool catches every now and again, it can affect the quality of the print. In this case, when the spool catches, too little filament could be extruded, causing irregular flow from the nozzle.

If you use the system I described earlier, installation is easy. However, if you do not want to mount the spool holder using the easy-on bar clamps, you may encounter some issues with partially disassembling the frame to get the clamps in place. I strongly recommend using the easy-on clamps.

Print Cooling Fan

Recall that the cooling fan is designed to force air over the print to help PLA parts cool evenly to avoid layer adhesion defects. I discussed a print cooling fan in the “Fans” section. Indeed, you can see the print cooling fan for this printer in Figure 11-12.

If you plan to print with PLA, you should install print cooling fan. Finding one can be a bit of a challenge. Few of the early Prusa Mendel i2 X-carriages were designed with a fan in mind. Thus, you may need to find a fan mount (like I used) that mounts to the existing belt clamp bolts.

Installing the fan is normally not difficult, with the only challenge being routing the wires along the same path as the hot end, extruder stepper motor, and thermistor. If you have zip-tied everything nice and tight, it may mean taking all of that apart to route the wires. Be sure to mount the wires so that nothing touches moving parts. Recall that the print cooling fan mounts to the electronics board.

Z-height Adjuster

This is another item I’ve discussed as a generic upgrade. For the Prusa Mendel i2 in particular, it is an absolute must-have. You will find it much easier to get your first layer adhesion dialed in—especially so if your print bed base is wood (many are).

Installation of the adjuster depends on which adjuster you choose. If you go with the one I used, you will need to loosen the left-side smooth rod on the Z axis so that you can slide the adjuster mount onto the rod. Be sure to not move the threaded rods, because you will have to realign the Z axis if you do. You can see the adjuster in Figure 11-10.

Y-Axis Belt Tensioner

The Y-axis belt on Prusa Mendel i2 printers seems more susceptible to slippage than other designs. Or maybe it is just my luck to have several exhibit this behavior. A lot of this has to do with the belt clamps used to hold the ends of the belt. I recommend upgrading to a belt clamp designed to firmly grasp the belt. In other words, one with ridges that match the teeth in the belt. Figure 11-17 shows the belt tensioner installed.

Notice the switches mounted to the left of the adjuster. These are switches for the LED light ring and the RAMPS fan. This switch mount has been removed from Thingiverse (I don’t know why), but there are several others that are similar. If you want one, I suggest making it one of your first designed-from-scratch objects. It isn’t difficult to design and it is not trivial. It’s good practice for designing more complex objects. Or you can use the one listed earlier (thingiverse.com/thing:381392).

When looking for a belt tensioner, I wanted to find one that did not require dismantling the frame. The one I found is designed to mount around the existing Y-axis idler bearing, making it easy to install. The only issue that you may encounter concerns the belt clamps. I found that I had to loosen the belt to get the tensioner fully seated on the threaded rods. To do that, I had to disassemble the build platform, which is not trivial. It isn’t difficult, but it will take some time and it will require you to level your print bed once you reassemble everything. Since you are likely to encounter the same, I suggest replacing those belt clamps while you’re at it.

Print Bed Adjusters

Even if you do not have or plan to add a Z-height adjuster, there is one modification you must make to enable leveling the print bed. Most kits include some form of bolts to mount the heated print bed to a plate or subframe for the Y axis. Some, like the kits I used, do not include any form of adjustment. Thus, if you need to level the print bed, you have to use some form of shim or washer to raise the print bed to compensate for print beds that are not level (trammed). Not only is this a lot of work to remove the bolts and insert washers, but it is also imprecise given that the thickness of the washer may be too thick or too thin, leaving the print bed lower or higher on one side. What is needed is a more precise way to raise or lower any corner of the print bed.

There are dozens of examples of adding adjusters in place of the solid mount bolts. Most people tend to use a spring placed over the bolt with the heated print bed next, and then a lock nut on top; or perhaps reversed, where the bolt head is on top and the lock nut is below the print bed. Either way, to adjust the print bed you must use two tools when adjusting each bolt. A variant of this setup fixes the bolt through the Y-axis base and the lock nut on top. This means using fewer tools.

However, wouldn’t it be better still to have a solution that doesn’t require tools? I decided to make a variant of the spring mount, but not use springs. I threaded the bolts through the Y-axis base and placed a nut on top of the base to hold the bolts fast. I then used a thumb wheel to hold another nut placed below the print bed with a thumb nut on top. Figure 11-18 shows my setup. I use this on all of my RepRap printers.

You can use whatever hardware your want (metric or SAE). In this solution, I used a #6 bolt and (two) #6 nuts. The thumb nut on top is a brass #6 nut. All of these are available in most hardware stores. Since the Y-axis base is aluminum, I simply drilled the exiting M3 hole out (I used a #6 tap for my most recent builds). The thumbwheels are available on Thingiverse and there are many varieties. Search Thingiverse for the size that matches your hardware.

Installation of print bed adjusters may require removing the print bed and possibly even the Y-axis base plate. Since the goal is to make leveling the print bed easier, the extra work will pay off once you reassemble the Y axis. If you use a toolless solution like mine, you will be able to level your print bed very quickly, and more importantly, you will be able to get the nozzle the same height on all four corners.

Z-Axis Fix

I spoke about Z-axis wobble in an earlier chapter. Recall that most Z-axis wobbles manifest as noticeable ridges in the vertical walls. Figure 11-19 shows two cylinders (they are cylinders like a napkin ring). One was printed on a printer suffering from Z-wobble, and the other on a printer with a Z-axis fix.

Notice the object on top. This is before the Z-axis fix. That is, the Z-axis threaded rods are fixed-mount on both ends. Notice the ridges in the surface. This is the vertical surface of the object. These ridges form a harmonic that will resonate up the vertical surfaces, making them more like Ruffles than high-quality prints.

Now look at the ring on the bottom. This is after the Z-axis fix. Notice how the ridges are almost completely gone. If you look closely, you will see a very small harmonic (I cannot even measure it, but I can see it with a magnifying glass). With the fix in place, the print quality is where it should be and even a bit better than most examples I’ve seen.

When I first discovered this problem, I tried a number of temporary fixes, including using a flexible coupler on the motors, which helped considerably but did not solve the problem. I also tried to find perfectly straight threaded rods. After visiting a number of hardware stores, I’ve determined none are perfectly straight. To get precision threaded rods, you have to contact specialty hardware vendors, which means they will be much more expensive.

In the end, none of my attempts really fixed the problem and were merely treating the symptoms. It wasn’t until I read Richard Cameron’s article, “Taxonomy of Z axis artifacts in extrusion-based 3d printing,” in RepRap Magazine⁹ (http://reprapmagazine.com/issues/1/index.html) that I understood the real problem. It turns out the Z-axis upgrade included in my original kit introduced the problem by fixing both ends of the threaded rods. Thus, any flex, bend, or other irregularity is transmitted to the X axis and manifests as these harmonic distortions in the vertical sides of the object.

So how did I fix the problem? I freed one side of the axis! That is, I made it possible for the threaded rod to shift slightly on the bottom mount. This allows the threaded rod to move around without translating the shifts to the X axis. Figure 11-20 shows the original Z-axis lower mount that came with my kit and a replacement I made to accommodate a thrust bearing.

The part on the left is the original lower Z-axis mount that uses a 608 bearing. The bore for this bearing is 8mm. Typically, two nuts or a single lock nut is used to rest on top of the bearing. Most Prusa Mendel i2 build documents suggest tightening the nuts so that the weight of the axis rests on the bearings. Some printer build documents also suggest using a flex coupling at the motor mount. This helps, but the fixed mount is on the bottom, and since this is closer to where most of the Z-axis travel will be confined (the lower levels), any deformity can translate to the X axis. Yes, there is still flex at the top, but not enough to compensate for threaded rods that are not perfectly straight and properly threaded. Furthermore, the load on the 608 bearing is perpendicular to its specification. Thus, the bearing is the wrong design for this solution.

The mount on the right corrects these errors by using a thrust bearing with a 10mm bore. Not shown is the top bearing washer. This is placed on top of the bearing race. On top of that is an 8mm thrust washer. Two nuts are used to place about half of the load of the X axis on the thrust bearing. This allows the threaded rod to shift around on the thrust bearing. Lastly, I use a flexible coupling at the motor mount to complete the solution. Figure 11-21 shows the solution.

Once again, the goal of my solution was to make it possible for the threaded rod to move around at the bottom, and thus not translate the deformities of the threaded rod to the X axis. The rings shown in Figure 11-19 are from the printer depicted in Figure 11-21. As you can see, the solution improved the Z wobble greatly.

Sadly, installation of this upgrade will take several hours because you must unthread the lower threaded rods to get to the Z-axis lower mount. You will have to remove the crossbar located in the center bottom of the printer as well.

What could make this upgrade even more difficult is if you have additional parts or components mounted to the frame pieces that must be removed. Look at Figure 11-15 again. I had to remove a number of things to get to the Z-axis lower mount. However, I feel the upgrade was absolutely essential and has made this printer far better.

Prusa i3

The Prusa i3 printer is the latest iteration of the Prusa variants of RepRap design. The Prusa i3 improves on previous designs in many ways. Perhaps most important are little or no Z wobble, fewer plastic parts, more frame rigidity,¹⁰ and it is easier to build. Since this RepRap variant is fairly recent, most RepRap vendors will have parts and kits available.

Like the Prusa Mendel i2 kit, most Prusa i3 kits come with the bare minimum for building a 3D printer. Thus, you are likely to find features such as print bed and Z-height adjustment incorporated in the kit. Unlike the Prusa Mendel i2, you may not find as many upgrades. This is due in part to the newness of the Prusa i3.

However, what you will find are several variants of the main plastic parts. The original repository is located at https://github.com/josefprusa/Prusa3, but there are several variants available. I prefer to use the source or original design for the plastic parts incorporating variants when needed. More specifically, how do you know the variants improve on the original if you never use the original to know what needs improving. This goes for the upgrades too. You should resist downloading and installing upgrades just because they are labeled “latest,” “newest,” or “improved.” As we saw with the Z-axis lower mount on the Prusa Mendel i2, the latest isn’t always best.

That doesn’t mean there aren’t any options for upgrades. In fact, there are many, and many more being made available every week. I have made a number of improvements, some of my own design, to my Prusa i3 printers. Figure 11-22 shows one printer that I have upgraded recently.

Some of the upgrades are not upgrades in the sense they replace existing parts. Rather, most of the upgrades are improvements in the form of new features. The following lists the upgrades and improvements I’ve made to the Prusa i3 shown in Figure 11-22. I list links to the parts where available. You may notice some of these are the same as those used on the Prusa Mendel i2.

• Print bed adjusters: thingiverse.com/thing:16428.
• Z-height adjuster: (See details from earlier list).
• Borosilicate glass print surface: Various online retailers.
• Insulated print bed: Various online retailers.
• RAMPS fan: thingiverse.com/thing:30331.
• Graphic LCD panel: Various online retailers. Mount is from thingiverse.com/thing:287633.
• Power supply mount and cover: thingiverse.com/thing:396650.
• Z-probe sled: thingiverse.com/thing:396692.
• Relay mount: thingiverse.com/thing:396653.
• Endstop holders: thingiverse.com/thing:82519 and thingiverse.com/thing:82631.
• Spool holder and filament guide: (See details from earlier list).
• USB relocate: thingiverse.com/thing:237016.
• Filament cleaner: thingiverse.com/thing:16483.
• Filament guide: thingiverse.com/thing:287608.
• Y-axis cable strain relief: thingiverse.com/thing:200704.
• Z-axis flexible coupler: Various online retailers. Look for a 5mm to 5mm coupler.¹¹

Since this is the latest design for the Prusa design RepRap printer, I present an overview of some of the upgrades in the following paragraphs. I will also describe the must-have upgrades in the following sections in order of difficulty to install.

The LCD panel shown in Figure 11-22 is a graphic LCD from RepRapDiscount. This LCD is a bit larger than the character-based one and therefore a bit easier to read. It also has the ability to display low-resolution images such as symbols for fans, the heated print bed, and extruders. I mounted the LCD panel on the top-left corner of the frame, which makes the panel easier to get to—especially if the printer is on a shelf below desktop-level. Figure 11-23 shows the LCD panel mounting system (the photo was taken from behind the printer). You can find the mounts at thingiverse.com/thing:287633.

I like to keep my wiring and electronics neat and tidy. One of the things that initially bugged me about building 3D printers was the external power supply arrangement. My early kits used an ATX power supply that rattled around on my worktop in its all-metal case. It was always in the way. Ever since then I try to find some way to attach the power supply to the printer. Some designs don’t allow this—there just isn’t enough space on the frame to mount it (Printrbot Simple). This is almost true with the Prusa i3, but I observed several solutions that mounted the power supply on the right-side frame. Figure 11-24 shows the solution I made (thingiverse.com/thing:396650).

The same is true for the printer electronics. I don’t like designs that have the electronics mounted remotely. Fortunately, the Prusa i3 design has included a mounting point for the electronics (at least conceptually if not actually—some frames do not have the mount points drilled). All you do is mount your Arduino or other electronics to the frame, and you’re done. If you want to add a fan to your RAMPS like I did, you can take care of bundling the excess wiring at the same time. Figure 11-25 shows the electronics complete with fan (thingiverse.com/thing:30331).

Now that we’ve seen a few of the interesting upgrades, let’s look at my recommendation for must-have upgrades.

Y-Axis Cable Strain Relief

The X- and Y-axis wiring on 3D printers undergoes a lot of flex during printing. I have discussed how this can cause breaks in the wiring and failure of the components. Most heated print beds have heater plates that mount the wires in the front. More specifically, the lettering on the heater plate is oriented with the wiring at the bottom. Thus, some people route the wiring for the heated print bed from the front of the Y axis, down under the axis movement, and back to the RAMPS. But this places the cable in a precarious position and makes it susceptible to binding by the Y axis. It also creates a lot more bend than is necessary since the wiring must make a nearly 180-degree bend.

You can fix this partially by turning the print bed so that the wiring is in the rear. This allows you to route the wiring to the rear of the printer and to clear the obstructions. However, turning it upside down or left or right makes the orientation of the text awkward. If you’re like me, you want everything mounted so that it not only functions well but also looks right. But it also doesn’t remove the stress point. The wiring will flex less, but is still a concern.

I found a very nicely designed strain relief on Thingiverse (thingiverse.com/thing:200704) that allows you to route your wiring under the print bed between the Y-axis plate and the heated plate. Since I insulate my heated print bed, the wiring is not subjected to the heat of the heater plate. If you do not use insulation, you can route the wires under the Y-axis base plate and zip-tie it in place.

The part mounts to the Y-axis base plate with a single zip tie. It also has a cutout for a zip tie for the wiring. Figure 11-26 shows the strain relief installed. Notice how the plastic wire loom is secured to the strain relief mount.

Installation is easy, and except for disconnecting the wiring, it does not require disassembly. I recommend mounting the other side of the loom to the rear frame. There is plenty of room for the cable in that area and it keeps it from floating around the back of your printer. If you don’t have a setup like this, you should consider making the change before you start any long print jobs.

Flex Coupler

A flex coupler is a nice addition to the Prusa i3. Most kits use a short piece of tubing and zip ties to link the Z-axis motors to the threaded rods. This works, but it doesn’t allow as much freedom for flexing as I’d like. Fortunately, there are many examples of aluminum couplers milled with a concentric cut to for a spring-like flex point. Figure 11-27 shows the flex couplers that I used.

You can find these couplers on many RepRap online vendor sites. Installation does require removing the old couplers, lifting the X axis off the motors. If you are careful, you may not need to level your print bed after the installation, but I highly recommend you do so just in case.

USB Cable Relocate

Having the electronics mounted on the back of the frame makes it less likely they will come into contact with your hands or tools as you use your printer. However, the mounting orientation makes plugging in the USB cable difficult. If you move your printer or connect and disconnect it often, you will find this arrangement irritating (at least I did).

Thus, I designed a part to move the USB connector to the front of the printer. I used a USB panel mount cable with a male B-type connector on one end and a female B-type panel mount connector on the other. For me, a 12-inch cable was just about right but I’d recommend an 18-inch cable to give you some extra length. Figure 11-28 shows the part installed.

Installation is not difficult, but may require removing your print bed if you cannot move the Y axis far enough back to mount the clamp. I designed the clamp to be slipped over the top Y-axis threaded rod. If you have difficulty pressing the clamp over the threaded rod, you may need to loosen the rod enough to move the rod back to allow you to slide the threaded rod through the clamp. If you have to disassemble the Y axis or the print bed, be sure to level the print bed before you print.

Spool Holder and Filament Guide

A good filament management system is essential for smooth, even extrusion. The negative effects of a spool that has too much friction or even snags can be severe. Recall these can lead to uneven extrusion and poor print quality. In the most severe case, too much tension can cause extrusion failures.

The components of the filament management system are a good spool holder, one or more filament guides to keep the filament away from the moving parts, and a filament cleaner. The spool holder I devised for the Prusa i3 uses threaded rods that clamp to the aluminum single-sheet frame (thingiverse.com/thing:396669). Figure 11-29 shows the spool holder frame made from threaded rods, my own frame clamps, and the any angle threaded rod clamp (thingiverse.com/thing:30328).

The spool rides on the same cones from the Prusa Mendel i2 example shown in Figure 11-29 (thingiverse.com/thing:21850), but modified to remove more material. I also designed a wide filament guide that keeps the filament in the middle of the print area (thingiverse.com/thing:287608). It has a slight angle to allow the filament to pull freely and is designed to clamp to the top of the frame. I use the same filament cleaner on all of my printers (see thingiverse.com/thing:16483).

Installation of this upgrade is not difficult and requires assembly of the threaded rod supports. However, the threaded rods required are not a standard length (e.g., 12 inch). You can use standard 12-inch length threaded rods for the top rod, but the rod for the spool holder cones will need to be about 15 inches long. Similarly, depending on how long you make the top threaded rod, the vertical rods may require cutting to a custom length. Cutting the rods to length makes this upgrade a bit harder to do than some. If you don’t have any way to cut the threaded rods, use wooden dowels to mockup the build, and then take those measurements to your hardware store and ask them to cut the rods for you (or get a friend with a hacksaw to lend you a hand).

Z-Probe for Auto Bed Leveling

Another must-have upgrade is one that is very popular and indeed still evolving among 3D printer enthusiasts: auto bed leveling (or more correctly auto Z-probing). I demonstrated a similar system for the Printrbot Simple earlier.

There are a number of examples of Z-probe upgrades for the Prusa i3. Most use a servo with the endstop mounted on a short arm to rotate the endstop down when probing, and away or stowed when printing. I never liked this design for two reasons. First, most mount solutions for the servo get in the way of fans and lights, and makes the X-carriage a bit too bulky. Second, you must use a very good quality servo and have almost no noise on your electronics board (RAMPS).¹² That is, most servos I tested either chattered annoyingly or crept into the down position slightly during a long print. For these reasons, I felt there had to be a better way. Figure 11-30 shows my solution.

Notice that there is a new part riding on the X-axis smooth rods. It is a sled with an electromagnet and an arm that has an adjuster for micro changes to the Z-height. What I wanted was a solution that allowed the endstop to be docked when not in use. This sled concept achieves that. When probing the Z axis, the firmware first homes the X axis and then runs the carriage out to the maximum position. Once there, the electromagnet is engaged and attaches magnetically to a metal tab on the X-carriage. The sled is then towed to each position for the probe (all four corners and the center). When probing is complete, the X axis is moved to the maximum position and the electromagnet is disengaged. This docks the endstop out of the way. Figure 11-31 shows a close-up of the sled. The round device mounted in the center is the electromagnet.

The electromagnet is controlled by the firmware via the same pins as the servos. In this case, the pin is set to low or high to engage or disengage the electromagnet. However, since the electromagnet requires 12 volts, not 3 to 5 volts, I use a 12-volt relay with the servo pin as the trigger. Figure 11-32 shows the relay mounted to the back of the frame. You can find the mount on Thingiverse (thingiverse.com/thing:396653).

Wiring the system requires running wires from the servo pins to the relay, 12-volt power to the relay, and the electromagnet to the relay. The relay should be a board designed to be triggered with a logic signal; that is, about 3 to 5 volts at a maximum amperage of 40mA. You also must run the wires for the endstop to the RAMPS board. As you can see in Figure 11-30, I routed the wires on the right side of the frame to avoid snagging on any parts. Figure 11-33 shows the wiring diagram for the system.

The diagram shows wiring directly to the Arduino for clarity. When you route the wires to the RAMPS board, you will use the servo pins located on the bottom of the RAMPS next to the reset button. Figure 11-34 shows the location of the servo pins.

All of the parts for this system can be found on Thingiverse (thingiverse.com/thing:396692). The sled is designed with supports, so you can just download it and print it. The only part not listed on the site is the LM8UU printable bearings. There are several examples available on Thingiverse. I modified one to fit the sled and included the .stl for the bearing on Thingiverse.

You can also find a link to a video of the system in action. Also located on the site is information for modifying your firmware to use the sled and electromagnet. This code is continuing to evolve, so you should check Thingiverse for the latest updates.

There are two ways to modify the firmware. You can either modify your own copy of the Marling firmware or use my branch of the Marling firmware. I describe each below. I recommend reading both versions so that you understand how all of the parts fit together in the firmware.

Modifying Your Own Copy

Modifying your own copy of the firmware means you don’t have to reconfigure the settings from scratch. You can simply add the code needed to control the sled. The changes to the firmware require adding two new defines to the Configuration.h file and several changes to the Marlin_main.cpp file. The following show the changes to the Configuration.h file.

#define Z_PROBE_SLED
#define SLED_DOCKING_OFFSET 5

Here we simply define the use of the sled and specify the additional distance the X axis must travel past its maximum to dock the sled. This will vary from one printer to another, so you should run your X axis out to the maximum without the sled installed to check how much space is needed. You need only move the sled so that the endstop does not make contact with print bed when the Z axis is at the minimum position.

You can find the modifications to this file on the Thingiverse site in the form of a difference file (.diff), or simply a patch. To apply the difference file (patch), use the patch command in the Marlin folder. Make sure you are using the latest firmware from https://github.com/ErikZalm/Marlin.

Using the Modified Marlin Firmware

Using my branch of the Marlin firmware may be best for those that are building a new printer or those that have manually configured Marling in the past. It also may be easier to use this branch and copy your settings over if you are not familiar with how to patch source code.

For these cases, I have created a branch of the Marlin firmware that you can use instead of patching your own copy of the firmware. You can get my version of the firmware from https://github.com/oliasmage/Marlin.

Installing and Wiring the Sled

Installation of this upgrade is nontrivial, not only because it requires modifying the firmware, but also because it requires partial disassembly of the Z and X axes. At the minimum, you must remove the smooth and threaded rod from the right side of the frame, and then remove the right-side X-end. To do this, you must remove the X-axis belt. You can then slide the sled onto the smooth rods for the X axis, and then reassemble everything.

Wiring is also an issue, given you have to wire in a relay. However, if you follow the wiring diagram shown in Figure 11-33, you should not have a problem. If you use a different relay or one with pins defined differently, you may have to study the diagram closely and make necessary changes to accommodate your hardware choice.

Once you have the hardware installed, and everything wired and the firmware updated, you will be able to enjoy effortless Z-probing (auto bed leveling). Not only that, but since the Z-probe sled includes an adjuster, you can change the Z-height slightly without need to change the firmware settings or issue any G-code commands. Cool, eh?

MakerBot Replicator 1 Dual

The MakerBot Replicator 1 Dual is a fantastic machine. While it is a bit older than the latest MakerBot Replicator 2X (the only other dual extruder currently available from MakerBot), it is still a viable solution for those seeking to experiment with dual extrusion and printing with ABS. That is, the MakerBot Replicator 1 Dual is optimized for ABS. There are no fans for printing with PLA.

While the list of upgrades I’ve made to my Replicator 1 Dual is much shorter than the previous printers presented, these upgrades are key upgrades for anyone wanting a high-quality ABS printer on a budget. More specifically, if you want the capabilities of the Replicator 2X (e.g., an enclosure and upgraded extruder) but the cost is too high, you can save a lot of money by buying a slightly used Replicator 1 Dual and installing these upgrades. In fact, my Replicator 1 Dual has a higher print quality than an out-of-the-box Replicator 2X. Figure 11-35 shows a modified Replicator 1 Dual.

The upgrades for the printer shown include the following. Since most of these items are upgrades you can purchase, I also list links to the product web site. I discuss each of the must-have upgrades in the following sections in order of installation complexity.

• Upgraded heated print bed: bctechnologicalsolutions.com/HBP/index.html
• MakerBot Replicator extruder upgrade / filament drive: Search eBay for the vendor named cred8t
• AluCarriage Dual: http://shop.raffle.ch/shop/alucarriage-dual/
• Aluminum arm upgrade: bctechnologicalsolutions.com/arm-upgrade/index.html
• Enclosure: Hood (thingiverse.com/thing:26063), Windows (thingiverse.com/thing:30311)
• Adjustable feet: thingiverse.com/thing:249914

Figure 11-36 shows a close-up photo of several upgrades. I will refer to this image in the following sections.

MakerBot Replicator Extruder Upgrade / Filament Drive

The extruders in the Replicator 1 are the older Delrin plunger types. These are notorious for being finicky and difficult to keep working well. There are printable solutions available that work much better, but the best way to solve the problem is to upgrade to an all-aluminum plunger design. Figure 11-37 shows the upgrades installed.

The upgrade consists of a back plate, a spring, a lever with a small bearing, and two bolts. Figure 11-38 shows the upgrade installed on the stepper motor. This is the version for the Replicator 2, but the ones for the Replicator 1 are very similar.

Installation is pretty easy. You start by unloading the filament from both extruders, disconnect the stepper motors (don’t get them reversed!), and remove the bolts holding the fan and stepper motor. Be sure to cover your print bed with a towel in case you drop a bolt or tool.

Take the stepper motors out of the printer and install the new plate and arm as shown in Figure 11-38. The most difficult part is holding the extruder level closed far enough to depress the spring and allow the leftmost bolt to seat. Once done, reassemble and reload your filament. No other adjustments are needed.

If you are struggling with the original Delrin plungers or have upgraded to the printed version (which resembles the aluminum version), you may want to invest in this all-aluminum option. I can say with some authority that most of my extrusion failures with ABS have been solved with this upgrade.

Upgraded Heated Print Bed

The stock heated print bed is sufficient for almost anything you want to print. However, there is one thing I consider a possible design flaw: the build plate is not removable. This makes removing and replacing Kapton tape a difficult and frustrating experience. Fortunately, there is a solution! BC Technologies offers a replacement heated print bed that not only features a removable build plate (print surface), but also comes to temperature a little faster. You can see the new print bed in Figure 11-35.

The heated print bed is a bit longer than the stock unit, and firmware changes would be needed to take advantage of the additional surface area. However, I’ve found no reason to seek out this modification. Additionally, the vendor recommends keeping the temperature of the surface below 100°C. I set mine to 90°C and it works fine in that range. That is, a bit cooler than the default for the stock unit, so if you decide to get this upgrade, be sure to reset the default in MakerWare.

The removable build plate is really handy. You can buy a second one and treat each with Kapton tape out of the printer using the wet method described earlier in the book. This, I believe, is worth the cost if you use your Replicator 1 Dual often enough to require changing the Kapton tape frequently.¹³

As a bonus, the heated print bed converts your four-post bed level adjusters to the newer three post of the Replicator 2/2X. This requires drilling a small hole in the wooden crosspiece between the arms, but BC Technologies includes a handy template (3D printed, of course).

Installation isn’t that difficult, but will require turning the printer on its side to get to the electronics. You will need to remove the electronics cover and disconnect and remove the cable for the stock heated print bed. Disassembly of the stock heated print bed requires removing the adjustable print bed screws and disconnecting the cable. Detailed instructions are included, and with some patience, you can complete the upgrade in under an hour. Naturally, you will need to level your print bed once you’re done.

Leveling the print bed with the new three-point system may seem a little awkward at first since the menus and operation of the printer does not change. However, if you follow the menus and ignore the bits about turning the rear left and right adjusters, and only change the one adjuster in the rear, you will adapt quickly.

AluCarriage Dual

The stock X-carriage for the MakerBot printers is made from injection-molded plastic. It holds up well for printing with ABS (and PLA), but if you want to print with filament that requires higher temperatures, such as nylon, the carriage may deform after extended periods of higher temperature extrusion. If you want to print with higher temperature filament, you will need to replace the stock carriage with one made from a material that can withstand higher temperatures. Carl Raffle offers a host of aluminum upgrades for MakerBot printers, including a replacement X-carriage (see the upcoming vendor spotlight sidebar).

Carl calls his upgrade the AluCarriage. It is a single CNC milled piece of aluminum that is a direct replacement for the stock unit. Like all of Carl’s products, the AluCarriage is of the highest quality, with an extreme attention to detail. I have several of these. Besides being a perfect fit and solution for higher temperature extrusion, it is a work of art. Carl offers the AluCarriage in a variety of colors. I chose the red option and I must say it looks really good installed.

Better still, the AluCarriage is available for both single and dual extruder models. That is, you can buy one for your MakerBot Replicator 1 Single, Replicator 1 Dual, Replicator 2, or Replicator 2X. Figure 11-39 shows the dual carriage that fits the Replicator 1 Dual and Replicator 2X.

Notice the bolt in the background. It has a special clamping aid at the top (3D printed, of course) to aid in securing the stepper motor and hot-end wiring.

The upgrade comes with all the needed parts (e.g., bolts). You will need some small amount of Loctite or similar thread-based adhesive for the small setscrews that hold the bearings in place. Otherwise, the normal tools that come with your printer will suffice for the install. A complete set of instructions are available on the product web site (http://shop.raffle.ch/AluCarriage_InstallationGuide_v2.pdf).

Installation requires removing the stepper motors and hot ends, as well as disconnecting the wiring from the existing top plate. To remove the hot ends, you need only remove the heater block that mounts to the stock carriage using two bolts—one on each side. Again, photos are included in the documentation to help you with each step.

Once the extruders have been disassembled, you then loosen the X-axis belt by loosening the bolts on the X-axis stepper motor and moving it toward the center of the printer. Next, you disconnect the X-axis belt clamp and then pry the stock unit off the bearings. The new carriage is then placed on the bearings and the setscrews are installed to secure the bearings.

Resist the temptation to tighten the setscrews beyond the point where the bearing is seated. This takes surprisingly little torque. Use Loctite to hold the setscrews in place. The best way to test the tension on the bearings is to move the carriage back and forth. It should move freely with very little friction. If it binds, the set screws are either too tight or the bearing is not seated properly (see the underside of the AluCarriage—there is an inset for each bearing).

Once the carriage is mounted on the bearings, you use the provided clamp with a bolt to secure the X-axis belt. Finally, reassemble the extruder and use the new mounting point for the wiring. You will need to level your print bed because the AluCarriage is slightly shorter than the stock carriage.

It is possible that you may need to move the Z-axis endstop if the distance needed to raise the print bed is more than the adjusters can handle. That is, you loosen the adjusters to the point where they turn freely and there is no tension from the springs. You need a certain amount of tension to keep the adjusters from coming loose. If this is the case, you can loosen the bolts for the Z-axis endstop (located in the center of the back plate about 4 inches down from the top) and move the endstop up. Move it up¹⁴ only one millimeter, and then tighten all bed adjusters and check the Z-height by homing all axes. If the print bed is still too low, move the endstop another millimeter and check it again. Keep doing this until the nozzle is within 2mm to 3mm of the print bed with the adjusters fully tightened. Once you reach this stage, level the print bed.

Aluminum Arm Upgrade: Replicator 1

There has been quite a lot said about the stock Z-axis arms in the MakerBot Replicator 1, 2, and 2X. Like the X-carriage, they are injection-molded. However, since the arms are designed with a 90-degree (or thereabouts) bend, the combination of the material, length, prolonged use (especially with a heated print bed) and rapid movements of the printer can induce a slight sag—and worse, vibration harmonics that can affect print quality.

Fortunately, there is a solution for the problem. BC Technologies Solutions offers aluminum bed arms that are CNC milled from aluminum. They are a direct replacement for the stock arms and come with all the hardware needed. You can see the aluminum arms in Figure 11-30. A more detailed photo of the arms is shown in Figure 11-40.

Extensive, easy-to-follow installation instructions are included with the upgrade. BC Technologies also installs the new bearings, so you don’t have to do that either—but you may need to add the bearing retainers. You also don’t need any additional tools. The tools that came with your printer will suffice.

The tricky part of the installation requires turning the printer on its side to remove the cover for the electronics. This isn’t difficult, but will require you to secure all loose attachments and accessories (spools, spool holders, glass plates, etc.). You will also need to remove the heated print bed.

The remaining disassembly steps include removing the brass nut for the Z axis, smooth rod covers, and the smooth rods themselves. The process isn’t trivial, but you should be able to accomplish it with little consternation. I recommend setting aside about two hours to complete the installation. Once assembled, you will need to level your print bed.

The aluminum arm upgrade is a major upgrade, and the price reflects the high-quality machinery that goes into each part. I think the price is reasonable given this and the simple fact that it completely solves the problems with the stock arms. In fact, I think this should be the number-one upgrade for all MakerBot Replicator 1, 2, and 2X printers.

Enclosure

The final bit that you need to make the Replicator 1 Dual equivalent to the Replicator 2X is an enclosure. The Replicator 2X comes with a hood and windows for the left, right, and front sides. Adding an enclosure to the Replicator 1 Dual not only gives it the same feature available standard on the Replicator 2X, it also helps prevent lifting and similar problems from drafts or unstable ambient temperature around the build area. You can see this upgrade in Figure 11-34.

I list this upgrade last because it requires that you mark, cut, and drill acrylic. If you do not have experience with cutting and forming this material, the build of these upgrades could be a challenge. If you do not feel comfortable cutting acrylic, I recommend asking a friend to help you, or to look online for a set already cut. I have seen several vendors selling complete kits of acrylic. Some are similar to those shown here, but all accomplish the same goals. Unfortunately, I don’t see these very often, so you should check online auctions and similar sites regularly.

The hood assembly isn’t difficult once the parts are cut and drilled. Printing the supporting parts for the hood can take a few hours (about six to ten, depending on your print speed) but assembling the hood and fitting it is straightforward.

The windows pose a similar challenge for cutting them out. I chose to use the front window from the hood kit and the side windows from the hinged version. In this case, I had to cut two windows from thinner acrylic sheets. The hinges and latches are easy and quick to print, and assembly is easy. I recommend using a small dab of super glue to hold the hinges and latch to the acrylic.

Once the enclosure is complete, you should notice an immediate improvement in several areas. First and foremost, temperature control should be more even, the odor from printing with ABS will be somewhat reduced, and you may see some increase in print quality for larger parts or parts with thin protrusions. For all of these reasons, a full enclosure is a must for a Replicator 1 Dual.

MakerBot Replicator 2 (and 2X)

The release of the MakerBot Replicator 2 (and 2X) printers was a milestone event for professional-grade 3D printers. These models have significant upgrades over the Replicator 1, including a more rigid steel frame, an upgraded print bed system, and a host of smaller changes that, together, make the Replicator 2 a must-have upgrade for owners of the Replicator 1 and anyone who wants a better class of printer. The Replicator 2 is the fourth generation of MakerBot printers.

I have a MakerBot Replicator 2 that I have modified extensively. Figure 11-41 shows my own Replicator 2. No, it isn’t a Replicator 2X! It’s a Replicator 2 with a full enclosure.

Even though MakerBot has since released the fifth-generation printer, which marks yet another step up in sophistication and capability, the Replicator 2 is still a very viable platform for 3D printing. If you are looking for a bit of a price break, you can find many used MakerBot Replicator 2 printers, some with very little hours, on online auction sites. In fact, the price break is so good that you can add a number of upgrades to the Replicator 2 to achieve even better print quality than the newest models—at a discount. Let’s see how we can save some money and improve the Replicator 2 at the same time.

On the other hand, if you really want the newest features, such as live video of your build and network printing capability, you may want to invest in the fifth-generation model. Frankly, I’ve found that these features are still a bit of a novelty (well, maybe not the network connectivity). But if you want these features, you should consider the latest offering from MakerBot.

However, let’s say you’re like me and those newest gee-whiz features are not tipping the scales of your buying power. The following describes a number of key upgrades you will want to consider if you want to improve your MakerBot Replicator 2 instead of buying the latest model.

The upgrades for the printer shown are extensive for this model. Indeed, I’ve taken this printer quite far down the upgrade path. I’ve upgraded just about everything except the heater block. But there is an upgrade for that too (http://shop.raffle.ch/shop/hot_end/). Since there are so many upgrades, I will highlight a few of the more interesting ones, and then discuss each of the must-have upgrades in the following sections in order of installation complexity. Figure 11-41 shows a close-up view of most of the upgrades. I will refer to this figure in the following sections.

• Upgraded print bed: Various online vendors.
• MakerBot Replicator 2 extruder upgrade: http://blog.karaskustoms.com/2013/06/makerbot-replicator-2-extruder-upgrade.html.
• AluCarriage Single: http://shop.raffle.ch/shop/alucarriage-single/.
• Aluminum arm upgrade: bctechnologicalsolutions.com/arm-upgrade/index.html.
• Alu-X-ends: http://shop.raffle.ch/shop/alu-x-ends/.
• Spool holder: thingiverse.com/thing:119016.
• Enclosure: (hood and panels) http://additivesolutionsllc.com/?cat=3.
• X-axis bearing idler: Search eBay for “3d Printer X-End Idler Kit” and the seller “almws6”. You may have to check frequently because the vendor often has limited quantities for sale. Contact the vendor via eBay’s messaging system for updates on availability.
• Adjustable feet: thingiverse.com/thing:232984.

One of the most interesting upgrades available for the MakerBot Replicator 2/2X are replacement X-ends. Carl Raffle offers a set of CNC milled aluminum X-ends in a variety of colors (http://shop.raffle.ch/shop/alu-x-ends/). Figure 11-42 shows a close-up view of the X-ends installed.

These pieces look great and work better than the stock units. However, the added benefit isn’t as dramatic as an extruder or bed arms upgrade. These units will reduce ringing of the X-ends. That is, a minor harmonic effect from the X-ends flexing slightly when the X-carriage changes directions. Granted, the improvement is slight, but if you are seeking perfection with your MakerBot Replicator 2/2X, you should consider this upgrade.

Also shown in the figure is a replacement X-end idler pulley with a small bearing installed. This upgrade will eliminate the need to lubricate the X-end idler pulley. If you use your printer enough to require performing preventative maintenance often, you may want to consider this upgrade. You can find these on popular online auction sites.

Now that we have seen a couple of the more interesting and exotic upgrades, the following describe those that I feel are essential and must-have for owners of the MakerBot Replicator 2 and 2X.

Upgraded Print Bed

The MakerBot Replicator 2 came standard with an acrylic build plate. While the build plate is rather thick and looks cool with the LED lighting, many owners have reported issues with the acrylic plate. Some have reported their build plates are not completely flat. Others have reported that the acrylic plate can sag over time.

The most extreme cases of nonflat build plates are those with concave or convex areas. Needless to say, this condition would make leveling the print bed problematic. That is, you may be able to get the plate close to level, but the convex and concave areas will likely have a compressed first layer (convex) and lifting (concave) problems. Reports of build plate warping are less frequent, but when it does occur, similar issues with leveling the print bed, first-layer compression, and lifting may occur.

Fortunately, there is a very easy fix for this problem. Replacement print beds are available for the MakerBot Replicator 2. Most are glass. There are several variants out there ranging from normal, inexpensive glass that is close to flat (but not likely) but very heavy (much more than the stock plate), to those that use higher-quality glass that is very flat.

However, there is also a plate made from aluminum that I prefer over glass. The eBay vendor cre8it offers a replacement print bed made from aircraft-grade aluminum that is machined to be extremely flat.¹⁵ The aluminum plate is a direct replacement for the acrylic plate. So installation is trivial—just remove the old plate and insert the new one! Figure 11-43 shows the build plate.

The plates are available in two forms: a solid plate that you can use both sides for printing and a lightened version that has had excess material milled away on one side. The lighter version is considerably lighter, so if you have a weak Z-axis stepper motor or you notice some creep (down) on your Z axis, you may want the lighter version. Some owners have reported that this problem is much worse with the heavier glass replacement. The plates come finished in black with a coating that works well with blue painter’s tape.

Whether you like the aluminum plate or a high-quality glass plate, if your stock build plate is not flat, you owe yourself to replace it with one of these alternatives. It won’t solve all of your print problems, but it will make your printer much more consistent and easier to set up.

Enclosure

Aside from the dual extruders and the heated build plate (and upgraded power supply), the biggest difference between the MakerBot Replicator 2 and 2X is the enclosure for the Replicator 2X. The Replicator 2 does not come with an enclosure. However, it can benefit greatly from having one.

In fact, my experiments with an enclosure for the Replicator 2 have shown improved lifting control, better adhesion overall, and less sagging for wider bridging. Not to mention I can now use a house fan or place my printer near an HVAC vent without worry of the cooling effects of the air currents. So how do you add an enclosure to the Replicator 2?

You could call MakerBot and order the stock panels and hood from a Replicator 2X. The nice people at MakerBot will happily sell you such parts, but they will be expensive and you may have to request a service ticket to get them. I’ve ordered frame and panel parts from MakerBot myself. They are very helpful. If you decide to go this route, I recommend stating your intentions upfront. Don’t expect to be able to click a link on the web site to order the parts. These are not considered wear or maintenance parts, so you will have to special order them.

However, there is an excellent alternative. You can purchase a set of replacement panels complete with clear windows and a door, as well as a hinged, removable hood from Additive Solutions (http://additivesolutionsllc.com). These are often sold on eBay. Just search for “MakerBot Replicator 2 Panels” or “MakerBot Replicator 2 Hood”. The enclosure is so good that I’d say it is better than the stock Replicator 2X enclosure because the door on the front opens to the right (easier to use), and the hood lifts effortlessly and can be removed without tools or removing anything else—it just clips to the frame. The hood is well made and has plenty of room for the filament tube and wire loop. You can see the enclosure and hood in Figure 11-41.

The panels are acrylic and come in a variety of colors. I choose the black panels, but I think the blue and yellow look pretty sharp too (eye of the beholder, of course). The hood is a single piece of Vivak formed to fit on top of the printer. Figure 11-44 shows a better view of the panels.

Installation of the panels requires removing the original left, right, and front panels. You then assemble the panels using the instructions included with your order. All of the panels come with protective film, so the longest step in the process is removing the film.

The side panels have four bolts to secure the windows. It is best to thread the bolts so that the heads (hex) are on the inside. This avoids any possibility of snagging in the X-carriage wiring if you used one of the zip-tie solutions to fix the stress point.¹⁶ The front panel requires assembling the door with a handle, and mounting a magnet on the panel and door. The magnet is held in place with instant glue. My advice is to use that stuff sparingly.

The hood takes a bit longer because you have to print the hinge and handle mount. This can take several hours, so if you planned on buying the hood and popping it on when it arrives, you may want to start printing the parts for the hood while you are waiting for delivery. I printed the parts myself using medium resolution, but I think a lower resolution—such as a 0.3mm layer height and faster (115mm) print speeds—would work better. There is no need to make a museum-quality piece because the hinge parts are very large and you really can’t see them (they mount to the back of the printer).

Once the parts are printed, you have one more step that requires a bit more skill. You have to drill the holes for the handle mount and hinge. I recommend assembling the hinge and clipping it in place, and then placing the hood over the printer and pressing the hinge to the hood. Use a permanent marker to mark the location of the holes for the hinge. Then remove the hood and drill the holes. Use a drill bit slightly larger than 3mm to give you a bit of room to fine-tune the position. Next, you can use some blue painter’s tape to tape the handle mount to the hood and mark the holes accordingly. Drill those out with a bit large enough for the bolts included in the kit.

Installation will take some time and extra effort if you opt for the hood. The results will be readily apparent once you start printing larger objects. You should notice an improvement almost right away. Despite the extra effort, I feel this upgrade is an absolute must for any MakerBot Replicator 2 owner.

AluCarriage Single

The X-carriage upgrade is the same for the Replicator 2 as it is for the Replicator 1, except that you will order a single extruder carriage instead of the dual. See the preceding “AluCarriage Dual” section for a detailed description of this upgrade. Figure 11-45 shows the AluCarriage Single.

Recall that this upgrade permits you to print with higher temperature filament without worry about the carriage deforming from the higher prolonged heat. Installation requires taking the extruder apart and removing the stepper motor, fans, heat sink, and heater bar. You will need to loosen the X-axis stepper motor so that you can unclamp the X-axis belt.

Extruder Upgrade

The extruder upgrade is the same for the Replicator 2 as it is for the Replicator 1, except you only need one set. Of course, if you are upgrading the Replicator 2X, you can use the same set as the Replicator 1 Dual. See the earlier “MakerBot Replicator Extruder Upgrade / Filament Drive” section for a detailed description of this upgrade.

Recall that this upgrade provides improved filament extrusion with fewer failures and more reliable parts. Installation requires unloading the filament and then removing the stepper motor, fan, and heat sink. Once you remove the old extruder parts (e.g., the Delrin plunger mechanism), you can install the new parts and reassemble it. The total upgrade time should be about an hour.

Aluminum Arm Upgrade: Replicator 2/2X

Like the extruder upgrade, the aluminum arm upgrade is the same as that for the Replicator 1. However, the arms are slightly different, so make sure that you order the correct parts. See the “Aluminum Arm Upgrade: Replicator 1” section for a detailed description of this upgrade.

Recall that the arms will help reduce vibration and will not sag like the stock arms. Installation on the Replicator 2/2X takes a bit longer because unlike the Replicator 1, the smooth rods on the Replicator 2/2X are captured in a subassembly that must be removed as a unit. This will take you a bit longer than a similar upgrade for the Replicator 1. However, the instructions included with the upgrade are excellent and walk you through every step. Give yourself about three to four hours to complete the upgrade. Don’t forget to level your print bed when you’re done reassembling.

Summary

Owning a 3D printer can be a lot of fun. Whether you print gifts, solutions for your home or auto, or just enjoy tinkering with designs, a good 3D printer won’t let you down. However, if you want to take the printer a bit further or you want to save some money by adding features to your current printer, upgrading can also be a lot of fun.

This chapter covered the types of upgrades available, as well as suggestions for optimizing your upgrade experience. I also presented descriptions of several upgrades for several popular printer models. Even if your printer wasn’t listed, reading through the descriptions will help you see what is possible for your own printer.

The next chapter begins the final part of this book. The next two chapters are designed to provide you with the information you need to take your 3D printing experience beyond the stage of printing the test objects and canned objects you’ve downloaded from the Internet.¹⁷

Thus, the next chapter begins the journey with a look at how to create simple objects, combine several existing objects, and even how to finish your object by applying several techniques for sanding, painting, and improving your prints.

_______________________

¹As much as I detest portmanteau words like “framily,” I must admit defeat given I use the term “farkle.”

²Future 3D printer soap opera or literary gaffe?

³The eye of the beholder applies here. I’ve found some don’t like the graphic displays. I like them because they’re easier to read.

⁴Sadly, some of my upgrades have been spontaneous endeavors. With few exceptions, most of these were disappointing. At the very least, set your expectations based on a little research.

⁵The photos for this thing show a very nice enhancement to the wood frame.

⁶As mentioned in previous chapters, this should be called auto bed tramming since there is no leveling—as in making things ­perpendicular to gravitational force. Also, the process creates a software compensation rather than physically changing the print bed adjustment.

⁷You can modify the parameters in the firmware before compiling as well. See Chapter 4 for a description of configuring Marlin for your printer.

⁸I am right-handed and my wife is left-handed. As a result, I often sit on the right. Many of the lamps in our house are awkward for me to use due to their orientation. There is a profound difference in where objects are placed and how they are oriented depending on your dexterity preference.

⁹February 2013, Issue 1.

¹⁰With the possible exception of the Z-axis flex on the Y axis for the single-sheet version from a heavy spool mounted on top of the frame. If you plan to mount a spool on top, use some form of brace.

¹¹Most Prusa Mendel i2 use 8mm to 5mm flex couplers. Make sure the flex coupler is designed is for the Prusa i3 that uses a 5mm threaded rod.

¹²I tried a number of Arduino and RAMPS boards, as well as noise suppression circuitry. The noise suppression helped, but not enough for my expectations.

¹³I’ve encountered some who have never changed the Kapton tape.

¹⁴Moving the endstop up moves the print bed toward the nozzle when homed. Moving the endstop down moves the print bed away from the nozzle when homed.

¹⁵There is some variance, but the measurement is insignificant. I measured a mere 0.0025mm difference on mine.

¹⁶Can you guess how I know this?

¹⁷Even though I design many of my own objects, I never stop looking for things to print. If someone else has designed something I need (and it is licensed appropriately), I use it!