The second half of this question is "...from spare/scrap parts?"
I ask because I am trying to find something to do to keep my spirits up and that will let me tinker with things. About a decade ago I started an open-class robot combat league in my school district and it was mildly successful. I'd like to try and do the same where I work since I feel like some kind of basic "I made this from crap in the garage and things from Goodwill" robot event might be fun to try.
The goal here is that I am not going to drop ~$60 on a single motor or anything wacky like that and I don't expect my colleagues to either. I'd like to take some parts from a boom box or a remote controlled car and use those to build a bot. I'd also like to keep it simple so that I don't scare off any colleagues who might not know as much about robotics as me and the rest of us who've been doing this for a while.
So, back to the original question. I understand "how" to put together a basic spinning weapon with a robot, even one made from salvaged toy parts, but the one thing that has consistently killed me has been how to actually assemble it, specifically what the spinning mass gets mounted to. I am no good at building a free spinning axle mount or putting a gearbox together. I could probably pick one out of an appliance, but what's the best way to actually mount a spinning mass to the axle?
