Aftermarket SCT focuser.

Mike21 (Michael) · #1 10-08-2009, 11:28 PM

Hi all,

Why is it cloudy every night I get a new toy? If it was clear I wouldn't be up bothering you lot. Matt (Mowghli) from IIS put me onto ScopeStuff in the U.S which allowed this graft onto my Promak180. Looks good huh? Just in time for Jupiter's opposition.

renormalised (Carl) · #2 10-08-2009, 11:57 PM

Looks like a nice focuser....how robust is it??

g__day (Matthew) · #3 11-08-2009, 12:48 AM

Damn that looks good - I am sure you'll be delighted with it. A well focused SCT or MAK can be tricky to achieve - but very well worth it. When you're tack sharp Jupiter and Saturn will be great. Photocopy a Bhatinov mask onto transparency for your OTA and when the weather improves I'm sure you'll thing your scope has a new lease of life!

Mike21 (Michael) · #4 11-08-2009, 08:31 AM

Hi Carl,

The quality of GSO pops up time and again. I appear to be the only one who likes the stuff. Their RC's (I learnt that's short for Ritchey-Chretien) are apparently naffed. The only grip I have with this focuser is that its rotation about the long axis of the scope (I don't know what you call that) is a bit scratchy; I might have to attack it with the wet and dry yet, may be even the grease gun.

And Matt,

I whimped out. I'm buying two masks from The Ozstockman. Best I stay away from sharp impliments like razors.

And thanks to the other Matt for the idea of the adapter.
And lastly, to the Ian who is trying to sell his Promak180, would this alteration make you more interested in keeping yours?

mithrandir (Andrew) · #5 11-08-2009, 08:34 AM

Andrews (Lee sure can talk if the shop is quiet) have GSO focusers. I just put a two speed one on my ST80.

I was thinking of getting a GSO focuser for my C8 but it doesn't seem to have an SCT thread option on the eyepiece side.

If I put my focal reducers (6.3 or 3.3) on the front of the focuser I think I'd wind up with too much separation between the f/r and the CCD.

I think that means I need a JMI - probably an EV-1cm.

g__day (Matthew) · #6 11-08-2009, 09:01 AM

Off topic but my GSO 8* 50 right angle finder scope has beautiful optics - if that is typical of their gear I am impressed!

Mike21 (Michael) · #7 11-08-2009, 02:33 PM

Reading b/n the lines, it appears to me that GSO is good stuff, generally better that SW, but charges disproportionately more for it. Their mirrors are claimed to have smaller fractional wave error than many other producers, and probably achieve it, don't ask me to pick the difference. Their focusers, extension tubes etc are nicely finished and SW don't seem to manufacture "aftermarket" items like that; that I've seen anyway. BUT their scopes are not as good value for money. Another thread in this part of IIS suggests that their CF RC scopes (that's me showing off with my newly learnt jargon) are horse pooh. I guess, as with everything in life you have to judge each item on its own merits.

As soon as the heavens open up you'll all be hearing about how successfully my new focuser allows me to nail planets; particularly Jupiter.