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View Full Version here: : GSO linear bearing focuser


MattT
24-08-2012, 08:36 PM
After trying to decide between Moonlite or a Williams Optics focuser for the 6" frac this is what I did...got a GSO Linear Bearing focuser instead! Reviews on CN weren't that good on the old 10:1 focuser but this new one got the thumbs up.
Good points: Great value $250 landed at my door from Agena Astro in the US. Straight swap for the old R&P focuser, easy. Focuser rotates, something I thought was not necessary but used first time out made viewing easier. 10:1 reduction is really nice. The only negative, the draw tube is short and needs a 50mm extension tube for most eyepieces, so did the WO focuser. Nice addition to the big frac. :)
Matt

brian nordstrom
25-08-2012, 07:48 PM
:thumbsup: Looking good Matt , how does it feel in use ? it looks very well made .I have heard of these but never seen one in the flesh , so to speak .
Hope it gives you lots of trouble free use .:).
Brian.

omegacrux
25-08-2012, 09:36 PM
Hi again Matt
That would have to be way better than the standard focuser !
I know I'm not happy with mine , same scope but an f5

David

AstralTraveller
25-08-2012, 10:40 PM
I first put an after-market drive on the original focusser, which took out the hand-induced shake and so did improve things a lot but there was still image shift. After a few years the image shift was horrendous, keeping the tension right was impossible and it was basically clapped out. So I upgraded to a motor-driven Moonlite which made it a different instrument. I can get the focus much tighter than I ever could.

The two things that worry me about this GSO focusser are

1/ it is still manual. On a dobs it doesn't matter so much but at the back of a long refractor tube I think motors are the way to go.

2/ the holes for the mounting bolts pass under the drive shaft, thus meaning at those spots the contact area between the shaft and the bar is reduced. I don't know whether it matters in practice but it looks wrong to me.

Still it would be a big step up from the original - which wouldn't be hard.

MattT
05-09-2012, 09:57 AM
Have finally got to use the scope ....the curse of new equipment continues. Brian and David of Tassie it's a great bit of kit. Has made using the frac a whole lot easier no image shift, nothing moves at zenith, my biggest eyepiece a 28mm ES 68* and 2" diagonal stay put unlike the old R+P. Astral David, I don't notice any change in the focuser going over the inset screws and yes an electric focuser add on would be good. Bintel sell one from JMI, one day will check them out, but for now I'm content with it as it is. I know what you mean about long scopes like this and the vibrations. All I can do is give the focuser a big :thumbsup:
Matt