My first project I wanted to build when I received my 3d printer was a R/C Tank, or something very similar, such as an FPV Tank. So I set off with my Raspberry pi, testing how to control two DC motors, and how to view where you are going. Using two ESC's, a PWM the Raspberry Pi, and some code, I am able to control the motors. I still need to connect a web cam connected via USB so I can see where I am going... but so far so good. I already have a working prototype.
Don't mind the colors it'll be painted later :/ (was using up my beginner pack of multiple color filament)
FOR THE CHALLENGE:
This would be a great project for learning about 3d modeling and printing, electronics, coding, and sparking creativity. I have yet to finish mastering this myself, as it is a work in progress, but non-the-less it works, was a great build, fun to do, and my kids love driving it around. It has increased their interest into the fun world of fun DIY projects, and drive of learning by doing, and learning by failing.
I set forth with the idea of making a FPV tank powered with a Raspberry Pi for driving around the office, house, outside for fun. I then started doing some research on the google and found vexrobotics.com They sell kits for robots, and prototyping kits for DIY projects, but I did not want to be constricted with their pre-made DIY kits. However I did find some tank treads there, so I purchased them, as you cannot have a tank without some treads. I then busted out the old K'nex toys from my youth, and built a basic frame to gauge the distance and placement for the 2 motors, 2 tread drive/idler wheel, and the 4 double and 2 single bogie wheel assemblies. From there I took measurements of the Pi, proto breadboard, 2 battery packs, 2 servos, the motors, and the bogie wheel assemblies. After I had all the measurements down, I headed to Tinkercad.com and started modeling. I knew with my makerbot mini I was constricted to a build volume of 3.9 x 3.9 x 4.9 so I had to use some ingenuity to create a modular design that I could then fit together like a puzzle. After a few learning curves with the printer, it is somewhat complete.
So after testing the prototype, I've learned that I definitely need to solve an issue.
Issue: Tank has a really hard time turning due to lack of torque/to much tred surface area touching ground.
Resolution 1 Primary: Add Gear Box from motor drive shaft to gear running treds. (didn't think about this and mounted tred drive gears directly on the drive shaft of the motor, thus, very minimal starting torque.)
Resolution 2 Temporary: Shorten the treds and frame or just treds, to limit the amount of tred surface area touching the ground.
By proping the tank up on its rear, like doing a wheelie or tredie? It was then able to turn, as the amount of treds touching the ground was reduced by about half.