Yeah the floor flipper was showing no mercy at that event, but at least the crowd enjoyed it! (@ Jarvis: When are the videos going up? I wanna see how Richie landed so I can get an idea of what's probably damaged )

On the batteries; the peak working current I'm ever likely to be drawing is probably around 30A, so one of those cheap 2200mAh 20C should be fine. I'll buy two just in case; at just over £6 each, I think my budget can stretch to that! As for the rest of the upgrades, I think I can manage them all without further spending (aside from maybe a fixings):

I've got some small aluminium box section for the self-righting wings; the rest is just string and elastic bands!

I'm planning to build the front drive belts using some slightly springy, heavy duty string sprayed with belt dressing (The round belts on RS were ~£13 for 5m, and could only take 5Kg of force unless you went to the really expensive stuff). I'm probably gonna have to do a fair bit of experimenting with the drive belts to get something that works reliably, but if they fail in a fight Richie'll still have drive, so it's not too big a problem.

As for spinner proofing, I'm planning to securely attach some ablative bulkheads to the chassis (Aka, bolt on some 2x2 from the firewood pile; gotta keep up the 'rustic' feel :L)

I'm gonna try and keep it looking like a fighting robot rather than just the heavy duty arts and crafts project it seems to be turning into; this is quickly becoming an exercise in 'Redneck' engineering at it's finest