Update - It's allliiiiiiiiiiiiiiiiiiiiiivvvvee

I'm a happy chappy; managed to give Drumroll II a quick test drive tonight and it is unbelievably nippy. Was only doing it in my room so I couldn't get a decent shot of it driving in a straight line, but the spins on the spot illustrate how fast this thing is!

http://www.youtube.com/watch?v=l8u8sYpLRwM

And the best thing is, that was only on one battery pack and therefore half the voltage
Chances are though it will be nigh uncontrollable running on its full voltage so I'll probably have to crack out the dual rates and exponential setting.

So as you can see, the basic chassis has now been bolted together:



The good news is that it's square (give or take a millimetre or two) and very solid. Not weighed it on its own yet but if the end product is overweight there is room for weight loss. Still need to take a cut out for the belt to pass through for the drum which, along with mounting the brushless motor, will wait until the drum is fitted so I can get everything lined up properly.

Couple of holes in the sides to accommodate the drill motors:



And fit some home-made wheels:



Add a receiver, battery and wire it up:



And it was good to roll. It likes to wheelie (which will be eliminated with the weight of the drum and possible hardox outer armour) and I can't help but feel that, with the chunky wheels, it looks a little Tanto-esque at the moment

Anyway I'm pretty pleased with how quickly it's come together - it's taken a few days but only working a couple of hours a day. Still plenty to do on it but having it driving this early on means I can get plenty of practice in. Shouldn't need too much though, as the Scorpion provides some precise control. I still rate Electronize controllers but daaamn, the XL is nice