What to do when the focuser getting lose?

[malau]

I cant zoom out now and I cant use the small ratio (1:10) focus knob because I have to either screw it tight / lose but nothing in between.

Mine is SW 150.... thanks

[Joshua Bunn]

HI David,

I'm finding it a little difficult to follow what you trying to say. What is loose? Is it the drawtube or the focuser knobs? and what brand of focuser is it, or is it the stock one that came with your scope, if so, please describe your scope your scope better or show us a picture of the focuser.

Josh

[malau]

Hi Josh,

Thanks for attempting to helping me. The focuser is focuser crayford. What I mean loose is I either have to screw it tight or otherwise when I attach my camera, it will goes inside. I guess is drawtube (the one where you put the eye piece/camera) will goes inside and now I cannot use the knob to zoom out

my focuser is something like this http://www.bintel.com.au/Accessories/Focusers/Bintel-2--Crayford-Focuser-10-1--303mm-/499/productview.aspx http://www.bintel.com.au/Accessories/Focusers/Bintel-2--Crayford-Focuser-10-1--230mm-/498/productview.aspx

Thanks

[mental4astro]

David, these GSO made focusers can be a real pain in the bum. The entire useablity of the focuser is determined by those two small aluminium screws right along side eachother that sit underneath the draw tube. I have a dog of a time making real sense of these two, having had the same problem as you.

Best I can suggest, until someone with better understanding offers help, is to first deal with the screw furtherest away from the OTA (1 in picture below). Have it set a little firm. It will set the underlying tension & clutch in the focuser. Set it then don't touch it. The screw closest to the OTA (2), that is the screw you tighten or loosen to lock or free up the draw tube.

171669

It is a bit of a trial and error thing to set up. I have this same focuser on my 8" dob - it is a GSO scope. In the dark I still sometimes twist the tensioning screw, and I have a female-dog of a time restoring things...

I hope this helps.

Mental.