Rapman assembly part 9

There's not much left to do on the cartesian bot now. I have to mount the Y stepper motor (on the top frontmost corner), one Y drive belt and the X drive belt.

The Z belt took a couple of attempts and a fair bit of fiddling to successfully splice the ends together; the second photo shows the jig I threw together using scrap acrylic and some polymorph. That attempt failed because I tried to do the splice whilst the belt was under tension - whoops.

The last attempt was also nearly a disaster when I discovered that the belt went the wrong way around one of the diagonal rods; I ended up having to completely remove the rod to get the belt where it was supposed to go. And then completely disassemble the belt tensioner that was on that rod, because it was impossible to realign the rod with my measurement jig while it was still on there.

The tensioner is a bit of a problem, because the belt doesn't have enough slack to fit it in the appropriate place! I ended up having to remove some of the nuts in the tensioner to reduce it's profile, and I spliced the belt together with a two tooth gap instead of just a one tooth gap to make it a little looser... and the tensioner barely fits. I don't have enough spare belt to make a replacement Z loop - in fact, I seem to only just have enough belt for the remaining belts with no spare left over. So it's probably just as well I made the Z belt as tight as it is!