Crayford focusers for SCT's

[louie_the_fly (Stew)]

I'm looking to buy a Crayford style focuser for my Celestar 8 and have been looking at the GSP and Bintel ones. I'm after some reviews by people who have used them. Are they good value for money? Do they work OK?

At this stage I only do visual observing.

Stew

[Merlin66 (Ken)]

Stew,
I had the GSO/ Revelation 10:1 version for a while (I actually used it on a PST mod!) worked well, no issues.
But I must ask.....why a Crayford? For visual the standard focuser is usually OK...or you could fit a small DC motor or even the Feathertouch 10:1 knob.

[casstony]

I've owned two GSO crayfords which worked quite well. If you get one that's not quite up to scratch here's a tune up guide:
http://polluxchung.com/gso_crayford_fix/index.html

I like using a crayford on a SCT for the extra fine focus control, but they do chew up a bit of backfocus. The Starlight Instruments 0.8" travel focuser I have is only 68mm long including the part that screws onto the SCT cell, minimising loss of backfocus.(but it's expensive)

[louie_the_fly (Stew)]

Originally Posted by Merlin66

Stew,
But I must ask.....why a Crayford? For visual the standard focuser is usually OK...or you could fit a small DC motor or even the Feathertouch 10:1 knob.

Ken, I find the standard focuser on the Celestar 8 to be very touchy. When focusing you get almost there, then it's gone. I struggle with it a bit, & I've read that putting one of these focusers on makes a big difference.

I'm in the process of motorising the standard focuser as well. Sort of tinkering with that.

Stew

[Rodstar (Rod)]

Hi Stewart,

I used to own a Meade SCT (10" LX200), and I found the focuser knob created quite a bit of image shift. To remedy this, I went the route of a crayford focuser (in my case I got a Williams Optics 2 inch model - http://www.williamoptics.com/accesso...d_features.php ).

In short, it was a fantastic improvement. I loved it. The only complication in a fork mount design is that it can bump into the base of the fork - and may therefore restrict some observing around zenith.