Hi Lewis,

The current chassis height is 90mm, the drum is 114mm and the wheels are 75mm, so invertibility doesnt really work
However I have my reasons for having such small wheels and sacrificing invertibility.

The first incarnation of Drumroll (basically before it had the drum) had 100mm blue wheels but the robot was very fast, so much so that most of the time it was uncontrollable. The best way I figured to drop the speed was to decrease the wheel diameter, plus the 100mm wheels took up too much space in the new chassis. I had used a roll-cage in a previous competition and it worked flawlessly so I decided to keep the smaller wheels for increased controllability, then add a roll-cage to deal with the self-righting. I toyed with the idea of a self-righting arm or a second set of wheels (similar to Crushtacean) but they were too much hassle and too heavy. The roll-cage is lightweight and effective so Ive stuck with that.

However its still an issue that Im not fully settled with, and after having seen how other drumbots deal with invertibility (I was impressed with the design of Proteus, a US drumbot) when its comes time to give Drumroll a new chassis, I will be taking the invertible approach