|
I first put an after-market drive on the original focusser, which took out the hand-induced shake and so did improve things a lot but there was still image shift. After a few years the image shift was horrendous, keeping the tension right was impossible and it was basically clapped out. So I upgraded to a motor-driven Moonlite which made it a different instrument. I can get the focus much tighter than I ever could.
The two things that worry me about this GSO focusser are
1/ it is still manual. On a dobs it doesn't matter so much but at the back of a long refractor tube I think motors are the way to go.
2/ the holes for the mounting bolts pass under the drive shaft, thus meaning at those spots the contact area between the shaft and the bar is reduced. I don't know whether it matters in practice but it looks wrong to me.
Still it would be a big step up from the original - which wouldn't be hard.
|