Overview:
This project started as a challenge for myself. The robotics team I am mentoring was creating battle bots to learn about 3d printing, robot design, and also to have fun in the offseason. I was not planning on creating a robot because wanted time to work on other projects. I found myself procrastinating on my other projects, particularly while doing CAD, so I challenged myself to create a battle bot in one weekend. This project was completely designed in CAD in just one weekend.
I modeled the design after Tombstone. It is a really simple robot that always seems to do really well in the show.
The robot was designed to be printed as 100% infill for maximum strength. The frame is split into three pieces main pieces. The top and bottom sandwich the frame, this design seemed to work great and was also super easy to assemble and print. The drive motors had two frame pieces that sandwich the motor. The weapon was also printed with 100% infill and accepted a 3/4in bolt to deal some damage.
We held a mini battle bot tournament to inspire the local middle school robotics team. Here is a video of the event: https://www.youtube.com/watch?v=EomnJFpB6l8&t. I was happy to see that the only damage my robot sustained was when we tried a different style bolt in my weapon. It was not the correct thread and we tried to use some tape to shim the bolt in. The bolt collided with some 3d prints and bounced back hitting the robot causing the crack in the picture above.
Some design takeaways for the projects are:
- Don’t put the on/off switch by the weapon (huge oversite)
- Print lots of small fittings on pieces that fit together
- The weapon meshing with the motor was the hardest thing to model
- 100% infill parts are much stronger than you might think
- During CAD make the history of a part clean to allow for changes down the road