Motor screwed on, so time to check that it all fits on the axle. With it lashed-up to the chassis I took the opportunity to put a tiny drop of oil on the motor bearings and give it a run for half an hour to bed it in a little. It cogs a bit with a feedback controller.
Being as it was the 1st of April and the clocks bounced forward over the weekend .... time to fit the springs. I just tinned the part and touched it into the existing solder around the bearing. Note that I've given in and started reading the instructions again.