crayford slip?

[estwing]

reverlation 10:1 seems to stop winding in half way down, if it's fully in, it has to be manually pulled out before it grips and then can be wound out. fixable?or is something broken:(

[AndyH]

Sounds like the tension needs tightening up?

[estwing]

please tell me which one it is as there's 8 on the barrel!

[AndyH]

Hi.

Sometimes crayfords have either one knurled thumbscrew and a grub screw, or two thumbscrews, both in the middle of the base of the crayford. Usually the tensioner is the one nearest the eyepiece end, directly over where the drive shaft runs.

Andy.

[AndyH]

Pic shamelessly borrowed from AgenaAstro.

Hope this helps,

Andy.

[AndyH]

[umadog]

Agreed: it's unlikely to be broken. Crayfords don't have a rack and pinion and so work by tension. If the tension decreases then it will slip. You find the correct set screw, increase the tension, and all should be good once more.

[R1gel]

Also make sure the tube lock is not too tight, should be tensioned off for movement.

Thats's the knurled screw just below the tensioning grub screw in the photo above.

[AndyH]

In the past when I had a crayford with only one thumbscrew was the following.........

if the threads are the same, swap the grub and thumbscrew over. I rarely if ever use the lock screw, so to my mind it was a waste, sitting underneath doing nothing. This is especially handy if you swap from a heavy eyepiece/accessory to a light one. Using a tiny allen key at night is asking for it to be lost in the grass.

Andy.

[iwatkins]

Adjusting the tension grub usually helps.

But also get the draw tube as out as it will go and check the flat section on the underside is clean.

Cheers

Ian

[estwing]

it was that screw andy..i was ready to put hand in pocket but you guys saved the day...S.G.L.