Update

So took a trip down to the industrial estate today to give Drumroll a run. The results were good; each battery pack went for about four minutes at full power before starting to show signs of running down, so I feel more confident that one pack will be enough to last a battle, and with two packs, I can have one ready and waiting to go into the robot as soon as its last fight is finished. The drum is also running very smoothly with minimal vibrations, so that's another bonus.

The test itself was just against an old computer scanner. Nothing challenging I know, but it's all there was lying about so it had to do. It smashed up well but after a few hits there wasn't much left of it to attack, so I resorted to just going nuts with gyro-dancing

Enjoy: