I can't see how you've got the drum on drumroll spinning? There's nothing connecting it to the motor!

Talking of chains, would a cog and chain (What's the technical term?) Be more efficient supplying the other wheels than a belt and sprockets?

Thanks for your help so far guys, you've all been amazingly helpful and I know it's cliche but thanks for using your own time to answer my questions!

Edit: Sorry I didn't see your post Jamie! Hmm, I think also that if I get a DX5e it'll last me longer, and therefore will end up being a better buy, by mixing do you mean you can change the drive type? Or max speed of the motors?