“Unskinny Bot” is my take on the tried-and-true horizontal bar spinner, just a rectangular chunk of metal that spins really fast and (hopefully) does a lot of damage to the other bot.
It will debut at Robot Battles 47 Microbattles at Dragon*Con in September 2013.
Step 1: Design
- dead shaft for the weapon: This means the weapon shaft doesn’t rotate; instead, the weapon blade and weapon pulley (which are bolted together) spin around the fixed shaft. There were a couple of reasons I chose this arrangement. First, that having the dead shaft clamped to the armor at the top and bottom might make it easier to change a weapon belt during competition. And second, it would have required some machining beyond my abilities and equipment to build a keyed weapon shaft with high-speed bearings at the ends.
- it had to fit within the milling limits: which are about 11″x5″ for the machine to which I have access
- battery cover for quick battery access: very important during competition!
- power switch: the rules require this if a bot has a powered weapon. I always forget this until it’s almost too late…
My original design called for belt-driven wheels (as shown in the CAD file) which are better at taking combat abuse. I found out late in the build that those didn’t allow enough internal space for the electronic guts, so I had to rebuild using direct-driven wheels. The upside is I had enough weight left over to put armor around the wheels.