GSO 10:1 Crayford Focusers

[Glenhuon (Bill)]

I'm looking at changing the focuser on my 150 Newtonian for a 10:1 Crayford type. Any problems with the GSO ones ? Funds are limited and its within the price range but don't want to end up with something thats not really suitable. The range of adjustment looks shorter on this type of focuser, so would it be advisable to look at getting some extender tubes as well.
Any advice is welcomed.

Bill

[Starkler (Geoff)]

You need to measure the max and min height of your existing focuser to see if the gso will cover your needed focuser height range. The other issue is that the curvature of the mounting foot I believe is suited to the tube of a gso 8" dob. Your 150 newt may have an ota tube that's too small.

[CoombellKid]

Originally Posted by Starkler

The other issue is that the curvature of the mounting foot I believe is suited to the tube of a gso 8" dob. Your 150 newt may have an ota tube that's too small.

In which case if you have a router, you can easily make an a adaptor plate
to suit.

regards,CS

[Glenhuon (Bill)]

I noticed the difference in tube diameter, the smallest one they have is for a 233mm tube. No router Rob, but the local "Mens Shed" might be able to help me out there as they have a couple of lathes as well, and in return I'll fix up the old puter they have and give the blokes a bit of puter training. Nothin like the ol' barter system .
I'll do the measurements and have a word with Andrews re the adjustment range. Thanks guys.

Bill

[GeoffW1 (Geoff)]

Originally Posted by Starkler

The other issue is that the curvature of the mounting foot I believe is suited to the tube of a gso 8" dob. Your 150 newt may have an ota tube that's too small.

Hi,

That curvature can be a problem, but it is simple to swap the mounting foot part with that from another GSO focuser (which agreed may not be relevant in this case). It is held on the main barrel by 2 grubscrews.

Cheers

[Starkler (Geoff)]

Originally Posted by GeoffW1

That curvature can be a problem, but it is simple to swap the mounting foot part with that from another GSO focuser (which agreed may not be relevant in this case). It is held on the main barrel by 2 grubscrews.

I dont believe that any 6" GSO newt comes with a 2 inch focuser option, so finding a pre-made foot to fit the tube could be a problem.

[GeoffW1 (Geoff)]

Originally Posted by Starkler

I dont believe that any 6" GSO newt comes with a 2 inch focuser option, so finding a pre-made foot to fit the tube could be a problem.

Hi,

True. The Meade Schmidt-Newtonian 6" OTA does, but I guess it is not a lot of use knowing that unless we can get those focusers as an accessory somewhere. Nothing much appears from distributors here from a brief look.

Cheers