I'll try to dial in more tension on the Crayford mechanism, but the difference between too tight to move and too loose to hold is only about 10 degrees of rotation of the tension knob.
Perhaps the traction bar on the focuser tube is not flat enough, or perhaps the tube tilts as it extends, reducing the friction. I don't know. I have read about tuning up your Crayford, and I might give it a try.
But the more I think about it, the more I think the solution is a rack and pinion. Obviously there is a huge difference between the el-cheapo R&P focusers on toy scopes and quality units on
So I am looking for recommendations. It needs to take 2" eyepieces and accessories. It doesn't have to be particularly low-profile, since the Paracorr extends the focal point enough for
Thanks for any suggestions.