My Orion XT10i focuser no longer slides up and down with the weight of an eyepiece in it. It slides up and down without anything in the focuser(loosely)but no longer has the weight(friction)to lift and eyepice with the knobs. It just slides down slowly. How do I increase the friction on it again? I took the bottom of the turn knob attachment off but the knob just slides in a plastic indented piece opposite of the screwed in cover.
Focuser for XT10i has no friction.
Started by flydudehsv, 12/02/2009 04:16AM
Posted 12/02/2009 04:16AM
Opening Post
Posted 12/02/2009 02:33PM
#1
Harry: I am assuming that your focuser is the standard Orion single speed Crayford. Crayfords use friction rather than gears to move the drawtube so if it is slipping it means that the preload (force) on pinion shaft is not enough.
The adjustment is simple, on the piece that pinion shaft cover there are two screws. One is the focuser lock and the second, the one closer to the scope, is an hex key set screw, that's the one that you use to adjust the preload. Tighten it until things seem correct.
It is possible that something has failed but I think that is unlike so try the adjustment first. If that doesn't work, I can further explain the workings.
These focusers also can benefit from "stoning" the draw tube flat so that it is really is flat.
Anytime one is working on a focuser, it is important to position the scope so that any parts that may fall do not fall into the OTA. This means the OTA should be horizontal rather than vertical.
Jon
The adjustment is simple, on the piece that pinion shaft cover there are two screws. One is the focuser lock and the second, the one closer to the scope, is an hex key set screw, that's the one that you use to adjust the preload. Tighten it until things seem correct.
It is possible that something has failed but I think that is unlike so try the adjustment first. If that doesn't work, I can further explain the workings.
These focusers also can benefit from "stoning" the draw tube flat so that it is really is flat.
Anytime one is working on a focuser, it is important to position the scope so that any parts that may fall do not fall into the OTA. This means the OTA should be horizontal rather than vertical.
Jon
Funding Member
