Assemble a goBILDA Outlaw Chassis Kit - Plus Raspberry Pi and 8BitDo Control!

Today we will explore the assembly and possibilities with the goBILDA Outlaw Chassis Kit. Check the image below to see the fully assembled goBILDA Outlaw Kit. There are heaps of other goBILDA Kits to explore too. There's the Low-Profile Ultra Rugged Recon Kit, the Articulating Front End Hammerhead Kit, the Ultimate in Agility 6WD BeeLine, and the Strafer (which sports Omni-Directional Wheels for maximum movement freedoms). 

This guide will go in-depth with the build experience with the Outlaw goBILDA Chassis Kit. The lessons I learned during assembly will be relayed here to make your experience as streamlined as possible. Then we will strap a Raspberry Pi Single Board Computer onto the chassis to provide some electronic control and smarts into this treaded vehicle robotics platform. We will finish off the guide by driving it around with a Bluetooth-connected 8BitDo Pro+ Controller and presenting interesting where-to-now ideas. See the contents of this guide below.

    - What you need
    - Hardware Assembly
    - Lesson Learned During Assembly (What I Wish I Knew Beforehand)
    - Adding Electronic Control (Raspberry Pi) 
    - Where to Now

When it comes to electronic control goBILDA has a fully fleshed-out RC control ecosystem. However, with such a phenomenal build material, I had to provide it with an equally phenomenal brain to control it. The best single-board computer in the world is the Raspberry Pi so that made the choice easy. With our laser-cut adapter mounting plate, you can attach a Raspberry Pi to any goBILDA structural support. We also have Adapter Mounting Plates for Micro:Bit, Raspberry Pi Pico, Arduino Uno, and any PiicoDev Modules.  So if you want to control any goBILDA chassis Kit with a Raspberry Pi (or any of the other supported ecosystems), this is how you go about it. Check the images below to see the Raspberry Pi 4 Model B controlling the goBILDA Outlaw Chassis Kit to drive toward the camera. 

If you are on the path to autonomous vehicles then the Raspberry Pi Single Board Computer is a perfect approach. Those with a keen eye will also notice an Oak-D Lite Spatial AI Camera mounted on top of the Raspberry Pi Stack in the image above. The Robotic Operating System (ROS OS) can run autonomous mapping with 2D Lidar or Optics (Camera vision) so we are getting very close to autonomy with our setup here. Keep in mind though that this is beyond this guide's scope.

All the goBILDA parts here are FTC (FIRST Tech Challenge) approved and we even have a comprehensive FTC Starter Kit. FIRST Tech Challenge teams are made up of 15 students between Grades 7-12 who are challenged to design, build, program, and operate robots to compete in a head-to-head challenge in an alliance format. The FTC Competition runs (in Australia) from June to potentially April. Participants are eligible to apply for $80M+ in college scholarships, so make sure your Local Schools and Universities are getting amongst it and taking STEM Education to the level it needs to be at.

Even if you are outside of the FTC Competition scope the goBILDA Chassis Kits are truly incredible platforms to build your next project. With the amount of freedom and jaw-breaking features that goBILDA offers, there is truly no other robotic platform that can compare. The goBILDA Outlaw Kit puts all other tracked robotic platforms five feet under. As always if you have any questions, queries, thoughts, or comments please let me know!

Below is a list of everything you will need to assemble the goBilda Outlaw Chassis Kit exactly to specifications. This includes all the necessary tools and whether the tool comes supplied. 

- The goBILDA Outlaw Chassis Kit 
- Allen Keys - Comes With Chassis Kit
- Simple Pliers
- Loctite Threadlocker (Blue) - Optional

All components were separately packed and many extra fasteners and hardware was supplied. All the components fit together gloriously and none of the aluminum parts have sharp burrs or edges. See the contents of the goBILDA Outlaw Chassis Kit labeled and laid out on the Makerverse Desk in the image below. 

In the above video, you can see the entire build process to get this goBILDA chassis created. Going through the build process to build the Outlaw I followed through exactly with the available Assembly Instructions which can be found linked. The process was intuitive with guidance from the instructions.

Here is a list of the tips I gleaned after building up the goBILDA Outlaw Kit.

• The Instructions are great and a quick speed read before assembly will be highly advantageous. At one point it requires you to go back and do repeat the steps again for the other Tracked Pod but Mirrored. If I had known beforehand I would've assembled both sides simultaneously. Having a good understanding of the process enables you to share the building process more fairly amongst a team.
• Organising components before the build based on when you will require them will help.
• You are provided with extra bolts, washers, and basic fastening hardware, so it is not an issue if some go missing during assembly
• You can use the holes to thread the Allen key through to more easily gain access to bolts. This makes tightening the setup with the two provided Allen keys significantly easier.
• The ends of the REX Shafts (the axles of this vehicle) do not require or warrant Screw caps (even though there are locations to screw a bolt into all of the REX Shafts).
• The bearings only come in two different types for this kit, with the only difference being the internal diameter so that it can deal with different shaft diameters.
• The goBILDA Pattern truly makes it easy to place components exactly where they are meant to be.
• Keep the components inside their zip lock bags until they are required for assembly. Foolishly I mixed up the spacers and found myself needing to measure multiple times their height to make sure I was using the 6mm Length Spacers and not the 8mm Length Spacers (or vice versa).
• I found it impossible to add the two fastening screws for the power-receiving belt pulley with the provided tools. Tolerances are very close here and the supplied Allen key was unable to get into there. This hasn't impacted the performance so far as the belt pulley naturally gravitates to the point on the axle of least resistance (right where it needs to be).
• During the build process, I felt a strong desire to use Loctite on all screws without washers. Loctite prevents screws from loosening up and falling off due to vibrating during operation. This I did not do for ease of reassembly/customisability. If this is the final design for your project and won't be changed, Blue Loctite for all the bolts and screws would be an excellent decision.
• Idlers can be added or moved in order to tune the handling of your tank. Idlers stop the tracks from deflecting at the point they are installed, creating lift when traversing objects. They also redistribute the load from the chassis too. By placing this idler in the middle of the track it allows our tank to become more nimble. Idlers would also be an awesome place to add suspension. 
• Even with my previous experience with Electronic Kits, I did feel a little overwhelmed with all the bags and components spread out, unassembled, before me. But fear not, all the components being in those bags makes putting the kit together intuitive and quick. As soon as I took the leap into starting the build all my concerns melted away. A very premium Kit Experience

From here we could utilise goBILDA RC components or we could break free (as I will) and utilise a different electronic control platform. Raspberry Pi Single Board computers are the greatest single-board computer available, so let's use one here. A Raspberry Pi 4 Model B 2GB will work perfectly.

Core Electronics has created a PiicoDev Mount for Raspberry Pi and goBILDA. This is a laser cut mounting plate (say a big thanks to Liam on our Core Electronics Forum) to easily mount Raspberry Pi Single Board Computers, PiicoDev Modules, and Raspberry Pi HATs to any section of goBILDA Aluminium Structure. There are a number of other PiccoDev Adapter Plates worth checking out. See this being done with a Raspberry Pi 4 Model B with a Motoron Pololu HAT attached to it in the image below.

Now our Raspberry Pi 4 Model B is the brain but we will need a Motor Driver to manage the 4 Large goBILDA Yellow Jacket DC Motors that comes with this Kit. I have previously done a guide on using the Motoron Dual High-Power Motor Controller HAT for Raspberry Pi (M2H18v20) with the Raspberry Pi which is exactly perfect for powering these four motors. HAT simply means hardware attached on top. Everything you need to know how to do this can be found in this linked guide. The only difference from that guide to this is how we are providing electricity to the DC Motors. For this today we are using the ROMOSS 30000mAH USB Power Bank to power the Raspberry Pi and a 12V Rechargeable Battery for the Motoron HAT and DC Motors. Doing so ensures that the system has enough current available to properly rip! 

See the Schematic below that I followed for the Motor and Battery Wiring for the Motoron Pololu HAT.

See the entire setup for the Raspberry Pi electronics system utilised for this goBILDA Outlaw Chassis Kit in the image below.

To set up the Raspberry Pi to work with these motors and HAT follow this guide here. Then with it powered and with a Bluetooth Controller Connected to the system run my |Outlaw-Bluetooth-Control.py | script to kick start the action. Find this Python Script and others in the download section below. Open and run this script with Thonny IDE exactly the same as the Control Large DC Motors with Raspberry Pi Guide. This guide also demonstrates exactly how to connect a Bluetooth Controller to a Raspberry Pi Single Board computer. With the script running press buttons on your Bluetooth controller (in my case the 8BitDo Pro+ Controller set up as a Generic Xbox Controller) and your Outlaw GoBILDA Kit will start moving! See this happening in the image below.

Our creative output really opens up when we take advantage of such a great robotic platform.

With that assembled we have the best robotic platform fully moving and functioning and the capability to take it to the next level. And there are so many directions we could go! For example, ROS2 control would enable our tracked vehicle to run autonomous mapping, navigation, and automatic driving with Lidar or Optic sensors. We could add AI smarts in the form of an OAK-D Lite Camera Module letting our robot recognise humans or objects remotely. We could remotely control movement or start patroling sequences through the internet. We could even add a Waveshare 4G HAT to enable control through text messages. We could add an ESP32-CAM so we can see the world from the perspective of our robot. We could even add GPS and IMU so we could get accurate speed and worldwide location data. We could even make it renewable by adding solar panels! Or fashion up a study recharge dock, allowing it to perform automatic patrol routines and then dock to re-juice the batteries when required. Surely it needs headlights as well, my guide on Driving High Powered LEDs would fix that right up.

You can see in the images below I have added the Oak-D Lite to a Pimoroni Pan-Tilt HAT and added it to our Raspberry Pi Stack. I talk about the 3D printed mount I made in my Oak-D Lite Set Up Guide, check there for the STL file. Check this guide on the Pimoroni Pan-Tilt HAT to get right into the action of controlling that particular component. Check below for images of this extra hardware set up on the robotics platform.

Other onboard sensors that we could add are 2D Lidar, optical floor tracking sensors, wheel encoders, infrared, cliff, bump, or slip detection just to name a few. Other goBILDA kits provide omnidirectional bases too, letting you have precision positioning when in constrained environments. With this rugged all-terrain land beast a wide variety of robotics applications in mining, agriculture, and environmental monitoring open up to us. We may soon be seeing it sowing the seeds of our future farmlands or spelunking into deep caves to bring food and water to trapped cavers. Or maybe tugging a pram around when the little ones need a walk.

GoBILDA is an open-source platform and you can get the CAD and STL design for every single component. This means you can create incredibly elaborate machines without even touching the physical hardware. It also streamlines 3D Printing, making it faster and easier to print components for goBILDA. There is also a huge amount of 3D printing possibilities here, I have yet to crack the seal, both to increase rigidity even further and to provide waterproof compartments for our electronics. But these are all future-where-to-now ideas. For today I'm ecstatic that there is a new fully operational tracked robot in this world. Thanks to goBILDA and Raspberry Pi!

Here is a Download Link for all the Python Scripts utilised in this guide and the Official Assembly Instructions. You may want the control script to run on boot, for knowledge on that check here. For even more ideas here is a fellow slowly recreating Disney's WALL:E from scratch with this exact kit.