Day 3. Spent all morning greasing the bearings and setting gear backlashes, etc. A few more tips follow.
Do the the worm gear backlash before doing the motor to worm gear mesh adjustment. Leave that bit until the worm assy back lash has been done and given a quick test, as you can't easily test the worm gear operation, using your fingers on the end of shaft, if the worm is engaged with the motor gear.
The motor to worm gear mesh is pretty straighforward anyway, gentle push on the motor housing to ensure good mesh while tightening the mount screws. Fine tune later will tell if that's OK.
So, time to put it all back together.......PANIC!
Someone had shrunk the RA shaft length by 15mm, meaning the nut wouldn't engage the thread when the assembly was inserted into the mount housing...
Spent all afternoon trying to find out what I'd done wrong, including total disassembly (sigh) of both worm gears to see if I'd accidentally swapped something. Nope. Came 4pm, bird feeding time, so gave up for the day.
5pm, birds fed and fire lit, time for a glass of merlot. After two mouthfuls, decided to go take another look at the mount. Tadah!
The little aluminium taper bearing collar thingy at the back, which was shrouding the RA shaft, really wasn't supposed to be there! It had moved back during my hammer and dowel persuasion of the RA bearing to seat in the mount.
Same hammer and dowel, more persuasion in the opposite direction on the taper housing and it was safely back inside the mount where it belonged.
Feeling much better, back inside to the warm fire and the brainstormer wine. Tomorrow will see the proof of the pudding. Well, of my hypertune, anyway.