Okay, so we're about five or six years late to this party, but it's time to build a Hobbyweight Drumbot! Click Back after viewing an image.
First up are the frame rails. These will be waterjet-cut from 3/8" 6061 aluminium by Team Whyachi.
There's a 1/4" 6061 back plate, 1/2" polycarb front wall, and the weapon motor mount is 1/4" 6061 too. The blocks between the inner and outer rails are UHMW, bolted through into the inner rails.
The drive train is a pair of simple Handiworks motors direct-driving the rear 3" wheels, and then those are chained to the front 4" wheels, which are on a dead axle.
The business end of the 'bot is a 3" 1/4"-walled drum, with 1/2" polycarb endcaps on a 3/8" steel dead axle. The teeth will initially be 2024 aluminium, but if there's weight they'll be replaced with 4130 steel. The weapon motor is a 900W brushless motor, which drives the drum using an XL (0.2" pitch) timing belt.
Partially assembled ... one piece of the design not in here are the Handiworks mounts, because we haven't figured that part out yet. It'll probably wind up being a slotted piece of 1/2" polycarb for the gearbox and another piece for the motor itself, both bolted to the back plate.
The battery is a 2.2Ah 3S 25C pack (shown in blue) clamped to the inner rail. The drive ESCs will be mounted to the drive motor mounts, and the receiver and weapon motor ESC will be mounted with the battery.
The top and bottom plates are 1/16" UHMW and should really just be to keep wires in and debris out - nothing should be mounted to them - the power switch is mounted to the right inner wall.
The final render, showing the 'bot in classic Team Radicus colours of black and purple. We're looking forward to trying this design out at Robothon at the end of October!