SW 150p focuser no longer grips

[palebluedot]

I can no longer focus my Explorer 150p. Turning the wheel has no effect unless gravity assists. Dismantling the focuser shows metal on metal between the focus wheel bar and the eye piece tube. Is that right, or should there be some kind of gripper there? or is it just wear and tear?

[Bizibilder]

Your scope has a "Crayford" focusser, so the "metal on metal" is quite correct. The focussing rod - attached to the focussing knobs - simply rolls against the "flat" on the focusser tube. You will need to get the exact info from another owner, but one of the screws in the focusser assembly is an adjustment screw that is used to get the friction needed to a nicety so the focusser will work properly.

[Psychobilly]

Here's a link to some info on adjusting crayfords...

http://www.teleskop-austria.at/information/rapo-120-bd/pdf/Crayford_adjustment_SW120ED.pdf

and there the Astroshed youtube videos...

Peter...

[MikeWilson]

Good tips above. In the first instance give the four mounting screws a good (not overly) tighten.

[palebluedot]

Ah... Found the tension screw. Thanks a lot guys.

[palebluedot]

Tried that first Mike. Thanks.

[Bizibilder]

While you have it in bits - try a little "white Lithium grease" (get it from a cycle shop) on the sliding parts - but NOT the focusser rod/flat which is a friction interface!

[palebluedot]

While you have it in bits - try a little "white Lithium grease" (get it from a cycle shop) on the sliding parts - but NOT the focusser rod/flat which is a friction interface!

I have some for the car doors Will it not spread about and end up where I don't want it?

[Bizibilder]

Shouldn't do - Just put on a tiny amount in all the right places and you should be OK.