Drive shaft assembly

Assembly of the printer has started with the drive shaft.  Having done a mock assembly of the drive shaft earlier, I decided this would be where I started.  The first step would be to prepare the drive wheels.  I quickly realised that all openings/holes on the printed parts are slightly smaller than they need to be, so I drilled out the rod-mounted wheel's centre hole to 8.5mm, in order to get an M8 bolt through to pull the nut into its captive hole.  It is a tight fit but using a bolt as puller (28mm washer on the bolt head on the other side of the wheel) makes it easy.

It is only possible to do one side like this, and the other side was more difficult.  I ended up pulling out the nut already placed, pulling in the other side nut, and then replacing the first nut (which now fitted much easier once having been in there).

I reamed the pipe mounted wheel hole with a 22 mm  drill bit, and mounted the pipe using two 3mm self tapper screws.  Enough space was left at the bottom for the flanged bearing.  It is important that the self-tapping screws need to be very short (or grind/file off the tips) as the 15mm copper pipe fits inside the 22mm pipe.

Quite predictably, I mounted the rod-mounted (bottom) wheel upside down, i.e. with the flat side towards the bottom.  A lot of unnecessary screwing and unscrewing was the result!