Slipping Crayford focuser

[jazzin]

I've been having issues with my focuser slipping are not moving in or out when I turn the wheel. Makes it hard to fins the focus point.

Anybody know how to fix this?

[StarBru]

Is it the stock Crayford focuser and on which telescope? Since you've been a member here for awhile, I take it you know how to operate the adjustment screws on the focusers to get the correct tension and you know the difference between the locking and the adjustment screws, correct? Agena Astro has a good article on optimizing GSO Crayford focusers that might help in your situation, I don't know for sure of course. Hope this helps.
https://agenaastro.com/articles/guides/ ... cuser.html

[Bigzmey]

Since crayford focusers are friction-based you need to find the right (and narrow) window where you tension is not too tight or too loose. I find it easiest to tighten the tension screw all they way and release in small increments until your focuser start to move. In my experience the right tension feels tighter than for R&P focuser, so you feel some resistance while focusing.

[yobbo89]

you might want to look into lapping the surface where the roller pin meets the draw tube if adjusting the tension dosn't work, i just wrap some fine grit sand paper over a file .

[helicon]

When I first got my GSO Dob with a Crayford focuser I had a problem with slop in its operation, to the point where it slipped continually until I locked it down every time I tried to focus. Kind of a pain. Later I learned to find a balance between the tension screws so it moved smoothly yet stayed pat after twisting the big focuser knobs. Lot's better. The operation is a bit more complicated than it seems at first. Good luck with it.

[Gordon]

All the information above is great! It will work well with most eyepieces. With that being said, I notice you are listing a Canon DSLR as part of your equipment. I found that the extra weight of the camera just didn't work well with a crayford focuser, so I changed to a "rack and pinion" focuser on both of my imaging scopes.

Here's the one I use on my newtonian: https://agenaastro.com/antares-low-prof ... speed.html NOTE: the antares attachment holes do not match up with every newtonian (skywatcher is what I have and the scope needed to have new mounting holes drilled for the antares).

and here's the one I use on my ES80ed refractor. https://agenaastro.com/catalog/product/ ... d_source=1.

Just make sure to double check for fit.

[jazzin]

I took the focuser down today and tried sanding the dar tube a little with a sanding stone. Put it back together and got it to work while the focuser isn't facing down. Because I image with a dslr, I always orient the OTA on the mount with the focuser facing down for balance reasons. And it still slips when I loosen the locking thumb screw when in that orientation. Works fine when it's not in that orientation.

Thanks for the suggestions!

[jazzin]

After a lot of trial and error and taking the focuser apart and the drawrube out, I've finally figured out how to fix the darn thing.

Thanks to this youtube video where the author thoroughly explains how to do what I needed to do.

[Richard]

I am not a fan of these toothless wonders , had quite a few and there are some that work well and other not so unless one' fixes' them, on the cheaper units like Skywatcher, GSO, etc , they give problems , one gets dust etc while using it and then you have to clean and adjust
A proper Rack and pinion works well for ever