After a few nights of deep sky stuff and periodic random
clunks in the dark I think I stumbled on a big reason why
the drive has been doing this.......grease!
I've been driving the worm gear around well past the 'clunk'
high spot that happened weeks ago and the gear had driven
itself to an ungreased section! Doh!
I had not greased the entire 360 degrees of worm gear after the
clutch face trim on the lathe.
Obviously, once it had reached the un-lubricated section, only the
remaining grease on the worm itself was supplying the lube!
Worms and worm gears don't go well just metal on metal
Greased and solved last night in the wee small hours.
Another problem has been the index point is now wrong.
A few nights ago one of these clunk/ tight spots had caused the
toothed belt cog to turn about 2 hours on the index 'clockface'.
I have to re-do a PEC curve set and re-index the wheel.
Steve