Hmmm, I can vaguely understand what you're describing, thanks Matt.

My Robochallenge wheels haven't arrived yet (even though they were meant to arrive on wednesday?) This is the second time products have been delivered late by them, has anyone else had this problem? Due to this I can't weigh out the internals properly as I don't have the wheels, would someone mind weighing out a pair of their 100mm blue wheels for me so that I have an idea of how much weight I have left for structure? Thanks!