© Harold Timmis 2021
H. TimmisPractical Arduino Engineeringhttps://doi.org/10.1007/978-1-4842-6852-0_8

8. Final Project 3D Model

Harold Timmis1  
(1)
Jacksonville, FL, USA
 

In this chapter, we will explore the 3D Modeling and printing of the NatBot. Just like the previous chapter, I will explain all new features used to create the 3D models. The first thing we will talk about is the requirements for the 3D chassis of the NatBot. Then we will look at the new functions used to create all the 3D models for the NatBot. Next, we will talk about each individual model and what measurements are important in order to make each of these mounts, brackets, and so on. After that, we will take a look at setting up the 3D printer to print each of these models using the Simplify3D slicer. Finally, we will look at the assembly of the NatBot which will include a short list of hardware needed in order to put together the NatBot. If you do have any issues with the model, don’t worry; the full model is supplied with this book. If you need to reference it, that is perfectly fine. So, now that the introduction is completed, let us take a look at the requirements for the NatBot.

Final Project: NatBot

The NatBot requires a modular chassis that will allow for later updates to be implemented when necessary. This chassis should be able to be 3D printed on most standard 3D printers. The NatBot chassis should resemble a rover-style robot with four wheels that can be independently controlled. See Figure 8-1.
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Figure 8-1

A fully assembled NatBot

Requirements Gathering (3D Model)

Naticom has put together a requirements document for the 3D model portion of the design. They are

  • Mounts for the motors should be independent of the chassis for easy printing and to make the NatBot more modular.

  • The PCB should sit on top of the NatBot chassis for easy access.

  • The GPS needs a mount hovering over the NatBot PCB.

  • The LCD needs a mount hovering over the NatBot PCB.

  • The Ultrasonic Sensor needs to be placed in the front of the NatBot chassis.

  • The NatBot needs to have a rover-like appearance.

  • The battery needs to be secure and located close to power input.

  • The NatBot needs to have a panel mount micro USB port for ease of programming the robot.

  • The NatBot should not be more than 200 x 150 x 175mm.

  • Wheels should be modular and generic and do not exceed 60mm in diameter.

Okay! So, we have our requirements; we should be able to think through them and start to design the NatBot. In the next section, we will discuss each requirement and come up with a solution for each.

Outlining the 3D Model Requirements

Alright, we have several requirements; let us go through each of the bullet points and start putting together a robot chassis:

  • Mounts for the motors should be independent of the chassis for easy printing and to make the NatBot more modular.

    This pretty much means we need to have the motor mounts separate from the main chassis to make them easy to print, and also if the customer (Naticom) wants to add or update the mounts later, they can. The motors need to be independent and should resemble a rover-style set of motor mounts.

  • The PCB should sit on top of the NatBot chassis for easy access.

    Another easy requirement, just make the PCB the “Lid” of the chassis; we will need to make sure that we have at least four of the five mounting holes on the PCB and have mounting posts, so the board is secured. We might even use brass inserts for more rigidity.

  • The GPS needs a mount hovering over the NatBot PCB.

  • The LCD needs a mount hovering over the NatBot PCB.

  • The Ultrasonic Sensor needs to be placed in the front of the NatBot chassis.

    We will need to create mounts for the GPS, LCD, and Ultrasonic Sensor; these can be fastened with hardware so the mounts should be able to handle vibration. We will also need to make sure each of these components is away from other hardware on the NatBot PCB. The Ultrasonic Sensor needs to be placed at the front of the NatBot which will also help with the rover appearance requirement.

  • The NatBot needs to have a rover-like appearance.

    As stated earlier, all features will give the appearance of a rover-style robot.

  • The battery needs to be secure and located close to power input.

    The battery will need to be in an easy access area and secured to the chassis; it should also be close to its input as the battery cable is not very long.

  • The NatBot needs to have a panel mount micro USB port for ease of programming the robot.

    The NatBot will have a panel mount micro USB port at the front of the robot to make it easier to program; without this panel mount, the user would have to remove the NatBot PCB every time they wanted to program it.

  • The NatBot should not be more than 200 x 150 x 175mm.

    The NatBot cannot be more than 200mm long, 150mm wide, and 175mm tall. This will be a small rover, but it will still be a challenge to meet this requirement with such a large PCB.

  • Wheels should be modular and generic and do not exceed 60mm in diameter.

They do not give us too much information on this, so we will just develop a simple 50mm wheel that will directly connect to the metal hubs we used for the previous project.

Fusion 360 Functions Explained

In order to create some of the 3D models, you will need to understand a few different functions in Fusion 360 that we have not used yet. The first function we will talk about is copying and pasting a 3D component, the second function is creating and using offset planes, and the third is using the Circular Pattern function. Let us get started with the first function, copying and pasting a 3D component.
  1. 1.

    First, open Fusion 360 if it is not already opened.

     
  2. 2.

    Create a new component and name it “Cube.” See Figure 8-2.

     
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Figure 8-2

Create a new component named “Cube”

  1. 3.

    Create a 5mm by 5mm by 5mm cube. See Figure 8-3.

     
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Figure 8-3

5 x 5 x 5mm cube

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig4_HTML.jpg
Figure 8-4

Select “Copy”

  1. 4.

    Right-click the cube component and select “Copy.”

     
  1. 5.

    Then right-click the Cube_Copy assembly and select “Paste New.” This will create a new body that is separate from the original cube. This is important if you want to modify just one of the components. This was used with the wheelbases of the rover. See Figure 8-5.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig5_HTML.jpg
Figure 8-5

Select “Paste New”

  1. 6.

    Notice that if you select the copied cube and change it, the original does not change with it. See Figure 8-6.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig6_HTML.jpg
Figure 8-6

The pasted component is a completely separate component

  1. 7.

    If you do want all of the components to match, then all you need to do is select “Paste” instead of Paste New.” See Figure 8-7.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig7_HTML.jpg
Figure 8-7

If you just paste a component, both components will share dimensions

So that is how you can copy a component; most of the time, you probably won’t mind if all of the components are identical, but sometimes (like in the case of the wheelbase models) you will want to copy a model just to modify that specific model and not the original. Next, let us talk about how to create an offset plane.
  1. 1.

    Using the same example from the previous section, select one of the faces on a cube. See Figure 8-8.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig8_HTML.jpg
Figure 8-8

Select a face on a cube

  1. 2.

    Select Construct ➤ Offset Plane. See Figure 8-9.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig9_HTML.jpg
Figure 8-9

Select the “Offset Plane”

  1. 3.

    Now move the offset plane to 10mm. See Figure 8-10.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig10_HTML.jpg
Figure 8-10

Make the offset plane 10mm from the cube

  1. 4.

    Now with this plane, you can create a sketch; you can even project faces onto the offset plane that can be used to make other bodies.

     
Offset planes can be used for a number of things for the rover; it was used to create the rover wheels. It made it easy to capture a center point for the motor shaft. Finally, we can talk about the last Fusion 360 function, the Circular Pattern function.
  1. 1.

    Create a new model in Fusion 360.

     
  2. 2.

    Create a cylinder with a diameter of 50mm and a height of 10mm. See Figure 8-11.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig11_HTML.jpg
Figure 8-11

Create a new component and make a cylinder

  1. 3.

    Create a new sketch and make a 10mm circle around the center point of the top of the cylinder. See Figure 8-12.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig12_HTML.jpg
Figure 8-12

Create a 10mm circle on the cylinder

  1. 4.

    Make this circle a construction line by selecting it and pressing the “x” key.

     
  2. 5.

    Draw a 3mm circle on the perimeter of the 10mm circle. See Figure 8-13.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig13_HTML.jpg
Figure 8-13

Create a 3mm circle on the perimeter of the 10mm circle

  1. 6.

    Select the Circular Pattern from the CREATE menu at the top. See Figure 8-14.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig14_HTML.jpg
Figure 8-14

Select “Circular Pattern”

  1. 7.

    Select the 3mm circle as the “Object,” and the “Center Point” will be the center of the 10mm circle. You will notice once you select these, you will have three circles on the screen; you can add more just by increasing the quantity. See Figures 8-15 and 8-16. Click “OK” when you are done, and you will see that these circles have been populated.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig15_HTML.jpg
Figure 8-15

Notice three circles populate on the cylinder

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig16_HTML.jpg
Figure 8-16

For the quantity, put “6”

  1. 8.

    Click Finish Sketch.

     
  2. 9.

    Select the six circles and press the “E” key. Extrude these holes to the bottom side of the cylinder. See Figure 8-17.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig17_HTML.jpg
Figure 8-17

Extrude to make six holes

Alright! That puts us in a good spot to start to talk about the various models you will be creating in this chapter. The next section will discuss each of these models.

Features of the NatBot 3D Model Explained

In this section, we will go through each 3D model that is needed to create the NatBot. Each part is explained, and each important dimension is discussed to make it easier to create the 3D model. Remember, you have some creative license here; you can make the NatBot exactly as this book does, or you can make the NatBot your own. It is entirely up to you. Let us get started.

NatBot Chassis

So the NatBot needs to have a few features that will hold the PCB and the battery in place. The motor assemblies and the GPS, LCD, and Ultrasonic mounts need to attach to it. Finally, there needs to be a place for a micro USB panel mount. The nice thing is the GPS, LCD, Ultrasonic Sensor, and the motor assembly mounts are all going to be designed by us, so we can make them any style we want. The same goes for the PCB, but we have already designed it a certain way, so we need to make sure we capture the PCB properly. The micro USB panel mount will need to have a spot made for it as we had to source that component.

Let us look at each section of the chassis.

Battery Holder

This is a simple holder as it captures the battery and then has four holes for zip ties to keep the battery contained. See Figure 8-18.
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Figure 8-18

Dimension of the battery holder on the NatBot chassis

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig19_HTML.jpg
Figure 8-19

Hole mount for wheelbase assemblies

The key measurements are the batteries’ length, width, and height.

Motor Assembly Mounts

The motor assemblies are our creation. Naticom has suggested they do want to keep it modular for future upgrades, and the PCB does include four servo motor channels, so we might want to make the mounts the same as a small servo, so if they want to use those mounts with servos, they can. See Figure 8-19.

The key dimensions are the small Servo that could be used later for the NatBot. This includes the length, width, and height of the servo motor.

Ultrasonic Sensor Mount

To mount this, we can just use two holes that will attach the mount to the chassis. See Figure 8-20.
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Figure 8-20

Ultrasonic Sensor Mount chassis mount

The key dimensions are the size of the screw.

LCD Mount

The LCD will be mounted on the top of the robot and needs to find a position on one of the PCB mounting posts and then be captured on one of the motor cable passthroughs. See Figure 8-21.
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig21_HTML.jpg
Figure 8-21

LCD PCB mount

The key dimensions are the M5 screw and the distance from the M5 hole to the motor cable passthrough.

Micro USB Panel Mount

The micro USB panel mount will need to have holes to mount it and a center hole that will give the user access to the micro USB port. See Figure 8-22.
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig22_HTML.jpg
Figure 8-22

Micro USB panel mount

The key dimensions are the length between the two mounting holes and the height and width of the access hole.

PCB Mounting

The PCB will be mounted using brass inserts to all for more rigidity in case the PCB ever needs to be removed and then reassembled. The PCB will dictate how large this chassis is as it needs to be roughly the same size in the length and width. Four of the five holes used on the PCB will have a post that will attach the PCB to the chassis. See Figure 8-23.
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig23_HTML.jpg
Figure 8-23

Make sure to use a DXF export in order to get the exact dimensions of the NatBot PCB

The key dimensions are the hole locations on the PCB, the motor passthrough locations, the length, height (with and without the Arduino attached), and width of the PCB. Using the DXF function to capture the PCB is a good practice as it will give you all of these dimensions minus the height of the PCB.

The last key dimension is the brass inserts that we plan to use for the project. See Figure 8-24.
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig24_HTML.jpg
Figure 8-24

Hole diameter of brass inserts

This chassis will also need a post to hold the Arduino to the PCB. See Figure 8-25.
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig25_HTML.jpg
Figure 8-25

Arduino post

Finally, remember that the NatBot can only be so tall; the current height of the PCB is 28.22mm with a plastic thickness of 3mm, which should make the NatBot strong enough to withstand some impact.

NatBot Ultrasonic Sensor Mount

The ultrasonic mount should be light and require little to no support material for 3D printing. Key dimensions include the length and width of the ultrasonic sensor, the hole positions of the ultrasonic sensor, and the height of the tallest component on the back of the ultrasonic sensor. See Figures 8-26 and 8-27.
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Figure 8-26

Ultrasonic Sensor Mount dimensions

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig27_HTML.jpg
Figure 8-27

Ultrasonic Sensor Mount dimensions (Cont.)

This mount needs to attach to the front of the NatBot.

NatBot LCD Mount

The LCD will be mounted to the top of the PCB. The key dimensions are the position of the M5 PCB hole and the motor passthrough width. Also, we need to make sure the LCD is at an angle that will make it easy to see when looking down at it. We also need to make sure the mount is high enough so that it does not interfere with other components and can be connected to the PCB using a dupont connector. The hole positions on the LCD are also important. Finally, make sure there is clearance between the LCD and any components on the back, including but not limited to the SD card holder. See Figures 8-28 and 8-29.
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Figure 8-28

LCD mount dimensions

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Figure 8-29

LCD mount dimensions (Cont.)

NatBot GPS Mount

The GPS mount will be above where the GPS connects. Key dimensions include the location of the GPS header on the NatBot PCB, the height from the PCB to the GPS module, the length and width of the GPS module, and hole positions on the NatBot chassis. See Figure 8-30.
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig30_HTML.jpg
Figure 8-30

GPS mount dimensions

NatBot Front and Rear Wheelbase

We will need four separate wheelbases: front right, front left, rear right, and finally rear left. Take advantage of the copy and paste features discussed earlier in this chapter. The key dimensions will be the size of the micro geared motors (length, width, and height), the motor shaft length and width, the mounting hole positions of the micro motors, the total height of the wheelbase model, the motor cable passthrough position, and finally the chassis mounting dimensions created during the chassis portion of development. See Figures 8-31 through 8-34.
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig31_HTML.jpg
Figure 8-31

Front wheelbase dimensions

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig32_HTML.jpg
Figure 8-32

Front wheelbase dimensions (Cont.)

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig33_HTML.jpg
Figure 8-33

Rear wheelbase dimensions

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig34_HTML.jpg
Figure 8-34

Wheelbase motor depth

The total height of the NatBot cannot exceed 175mm, so make sure you do not make these wheelbases too tall.

NatBot Wheels

These wheels will need to be attached to the same wheel couplers used in the first project of this book. Key dimensions include the motor coupler threaded holes and the distance between the wheel and the bottom of the NatBot chassis. See Figures 8-35 and 8-36.
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig35_HTML.jpg
Figure 8-35

Wheel dimensions

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Figure 8-36

Wheel dimensions (Cont.)

3D Printing the NatBot

Well , now it is time to test these dimensions and try to print the NatBot. In this section, I will explain what to print together, how to print, what infill % to use, and where to put support structures. Let us get started with printing the chassis:

Printing the chassis:

Infill % should be 25 to 30%.

Use PLA at 190 to 220C.

Estimated time to print: 4hrs.

You only really need to have support structures where the micro USB panel mount is because of the overhang. See Figure 8-37.
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig37_HTML.jpg
Figure 8-37

Printing the NatBot chassis

Printing the wheels and wheelbases:

Infill 25 to 35%.

Use PLA at 190 to 220C.

Estimated time to print: 7hrs.

Auto generate support material; use 2mm for the “Support Pillar Resolution” and 35 degrees as the “Max Overhang Angle.”

Also, turn all the wheelbases 90 degrees so that the support structure inside the micro motor cavity can be removed easily. See Figure 8-38.
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig38_HTML.jpg
Figure 8-38

Printing the wheels and wheelbases

Printing the LCD, GPS, and Ultrasonic Sensor Mounts:

Infill % should be 25 to 30%.

Use PLA at 190 to 220C.

Estimated time to print: 1hr.

The only part that needs support structures is the LCD mount; use 2mm pillar resolution with a max overhang limit of 35 degrees. See Figure 8-39.
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig39_HTML.jpg
Figure 8-39

Printing the mounts

That should be all of the printable components. The next section will discuss assembling the robot.

Fit Check and Assembly

Let us first talk about some hardware you will need in order to assemble this robot:

  • 4 x M5 10mm pan head screws (for PCB mounting)

  • 4 x M5-0.8 OAL 5.83mm brass inserts (for PCB mounting)

  • 12 x M2 10mm pan head screws (for wheelbase, Ultrasonic, GPS)

  • 14 x M2 nuts

  • 2 x M2 12mm pan head screws (for LCD mounting)

  • 2 x M3 10mm pan head screws (for micro USB panel mount)

  • 8 x M1.6 4mm (can be cut down from a longer M1.6 screw)

  • 4 x 30mm gasket or rubber bands (for wheels)

  • 1 x Adafruit micro USB panel mount cable (pn: )

  • 4 x micro motor couplers (pn: Servo City 545348)

  • 4 x micro geared motors (pn: Pololu 2209)

  • 2 x 145 by 2.5mm zip ties

  • 4 x JST SH Jumper Wire (pn: SparkFun GPS-09123)

  • 1 x GPS module (pn: )

  • 1 x Ultrasonic Sensor (pn: )

  • 1 x Adafruit OLED LCD (pn: )

  • 1 x 2Ahr Lithium Ion (pn: SparkFun PRT-13855)

  • 2 x 10 position dupont housing

  • 26 x female dupont crimps

  • 2 x 3 position dupont housing

  • Small piece of Velcro

  • 24 AWG wire

  1. 1.

    Press four of the brass inserts into the NatBot chassis using a small hammer or a vise to evenly push them into the PCB mounting posts. See Figure 8-40.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig40_HTML.jpg
Figure 8-40

Press the brass inserts into the chassis

  1. 2.

    Insert the micro motors into the wheelbases; they should fit snuggly. If they do not fit, try and use a file or X-Acto knifetm to clean the area around the motor housing on the wheelbase. If you have the rotary encoders for the motors, make sure they are already attached. See Figure 8-41.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig41_HTML.jpg
Figure 8-41

Insert each of the geared motors into the wheelbases

  1. 3.

    Using eight of the M1.6 4mm screws, attach the wheelbase to the micro motors. See Figure 8-42.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig42_HTML.jpg
Figure 8-42

Use the M1.6 4mm screws to attach the motor to the wheelbase

  1. 4.

    Attach the wheelbase prints to the NatBot chassis. They should be a bit of a tight fit, but if you are having trouble fitting them in, you can sand down the top a little to help them fit better. See Figure 8-43.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig43_HTML.jpg
Figure 8-43

Attach the wheelbases to the NatBot chassis

  1. 5.

    Use eight of the M2 10mm bolts and eight of the M2 screws to secure the wheelbases to the chassis. See Figure 8-44.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig44_HTML.jpg
Figure 8-44

Secure the wheelbases to the chassis using 8 x M2 10mm screws and nuts

  1. 6.

    Attach the Ultrasonic Sensor to the Ultrasonic Sensor Mount using two of the M2 10mm screws and two M2 nuts. See Figure 8-45.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig45_HTML.jpg
Figure 8-45

Attach the Ultrasonic Sensor to the mount

  1. 7.

    Attach the GPS module to the GPS mount using a small piece of Velcro. Use scissors to cut the Velcro to size. See Figure 8-46.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig46_HTML.jpg
Figure 8-46

Attach the GPS module to the GPS mount using Velcro

  1. 8.

    Attach the LCD to the LCD mount using two M2 12mm screws and two M2 nuts. See Figure 8-47.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig47_HTML.jpg
Figure 8-47

Attach the LCD to the LCD mount

  1. 9.

    Using crimpers, create a wire harness for the Ultrasonic Sensor. It will need 2 x 3 position dupont housings and 6 dupont female crimps. You will also need about 3 x 5in of 24 AWG stranded wire. See Figures 8-48 through 8-53.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig48_HTML.jpg
Figure 8-48

Cut off 1/8in insulation

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig49_HTML.jpg
Figure 8-49

Insert a wire and use pliers to gently squeeze the insulation crimp to hold the wire in place

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig50_HTML.jpg
Figure 8-50

Crimp the contact onto the wire

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig51_HTML.jpg
Figure 8-51

Finished crimp

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig52_HTML.jpg
Figure 8-52

Insert crimped wire into 3 position housing

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig53_HTML.jpg
Figure 8-53

Make sure the connector has this pinout

  1. 10.

    Create the wire harness for the LCD using 2 x 10 position dupont headers and 20 female dupont crimps. You will also need 10 x 3in 24 AWG stranded wire. See Figure 8-54. Use the same method to create the wiring harness as you did in the previous step.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig54_HTML.jpg
Figure 8-54

LCD cable

  1. 11.

    Attach the Ultrasonic Sensor Mount to the chassis using 2 x M2 10mm screws and 2 x M2 nuts. See Figure 8-55.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig55_HTML.jpg
Figure 8-55

Attach the Ultrasonic Sensor Mount

  1. 12.

    Put the battery into the battery holder and use the two zip ties to secure it to the NatBot chassis. See Figure 8-56.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig56_HTML.jpg
Figure 8-56

Attach the battery to the chassis using two zip ties

  1. 13.

    Attach the four JST cables to each of the four motors in the wheelbases and put them through the motor cable passthrough holes on the NatBot chassis. See Figure 8-57.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig57_HTML.jpg
Figure 8-57

Attach the JST cables to the four motors

  1. 14.

    Wrap each of the JST wire with a zip tie to make them a bit shorter. Do not tighten too much because you can break the cable. See Figure 8-58.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig58_HTML.jpg
Figure 8-58

Zip tie the JST cables to shorten them

  1. 15.

    Mount the micro USB panel mount with 2 x M3 10mm screws. See Figure 8-59. Then attach it to the MEGA 2560 Pro microcontroller. See Figure 8-60.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig59_HTML.jpg
Figure 8-59

Attach the micro USB panel mount

../images/271483_2_En_8_Chapter/271483_2_En_8_Fig60_HTML.jpg
Figure 8-60

Attach the panel mount to the MEGA 2560 Pro

  1. 16.

    Attach the NatBot PCB to the NatBot chassis and use 3 x M5 screws to attach the PCB to the NatBot chassis. See Figure 8-61.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig61_HTML.jpg
Figure 8-61

Attach the PCB to the chassis using three M5 screws

  1. 17.

    Attach the LCD mount to the NatBot by using an M5 screw. See Figure 8-62.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig62_HTML.jpg
Figure 8-62

Attach the LCD mount to the chassis

  1. 18.

    Connect the other side of the LCD wiring harness to the PCB. Use a multimeter just to make sure all contacts are making the proper connection. See Figure 8-63.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig63_HTML.jpg
Figure 8-63

Attach the LCD connector to the PCB

  1. 19.

    Attach the GPS mount to the chassis using 2 x M2 10mm screws and 2 x M2 nuts. See Figure 8-64.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig64_HTML.jpg
Figure 8-64

Attach the GPS mount to the chassis

  1. 20.

    Attach the Ultrasonic Sensor wiring harness to the PCB. See Figure 8-65.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig65_HTML.jpg
Figure 8-65

Attach the Ultrasonic Sensor cable to the PCB

  1. 21.

    Connect all of the motor cables to the correct connector on the NatBot PCB. See Figure 8-66.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig66_HTML.jpg
Figure 8-66

Attach the JST cables to the motor headers on the PCB

  1. 22.

    Attach the motor couplers to the four motor shafts. See Figure 8-67.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig67_HTML.jpg
Figure 8-67

Attach the motor couplers to the geared motor shafts

  1. 23.

    Attach the four wheels to the motor couplers. See Figure 8-68.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig68_HTML.jpg
Figure 8-68

Attach the wheels to the couplers

  1. 24.

    Add the 30mm rubber bands or gaskets to the NatBot wheels. See Figure 8-69.

     
../images/271483_2_En_8_Chapter/271483_2_En_8_Fig69_HTML.jpg
Figure 8-69

Add 30mm rubber bands to give tires more traction

Well, that should be it for the assembly of the NatBot; the only thing left is to write some software that will bring the NatBot to life. See you in the next chapter.

Summary

Alright, we covered a few things in this chapter. Let’s take a look at them:

  • Looked at the mechanical requirements for the NatBot chassis and mounts.

  • Brainstormed how we can bring this robot to life and make it look like a rover.

  • Took a look at all the important dimensions needed in order to create the NatBot chassis and mounts.

  • Went into what it will take to print each of these components.

  • Finally, we assembled the NatBot using a Bill of Materials (BOM).

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