Mass produced focusers are just that, made in mass with not near the quality control of better made focusers. So you can get one that is usable and you can get one that isn't usable. I have never used a GSO so cannot comment. I do however use Feather Touch. Yes, they cost more. Are they worth it? If you are serious about looking up, yes they are worth the cost. The Feather Touch that states it is 10:1 'will' be 10:1, time after time. Mass produced cannot begin to match this. Feather Touch has a limited lifetime warranty to the original owner. They're a phone call away and always have time for you. If something goes wrong in the milling of the Feather Touch, it's history. Not so with the massed produced, everything is used, nothing wasted, it is attached to the scope. When I buy the Feather Touch I am paying for far more than just a focuser. Those that failed and went to the trash, I paid for them. This ensures the product I receive is exactly as advertised. And they do last. Nobody can use/abuse like I can. I haven't had one fail yet, so when I need a focuser I know where to get one.

Yes, I like Feather Touch focusers. No, I'm not affiliated with Starlight Instruments at all.

Peace...

 

The reason you would swap a course focuser with a smooth, fine focuser is to easily achieve critical focus at high mag, especially with a fast scope. The feather touch focusers are nice, but in my opinion they are not 4x nicer! I'm just a regular Joe who does not like paying for items that are thrown in the trash. So, I'll take the GSO focuser. But, if you seriously abuse your equipment (wait..... that didn't sound good), you may want to opt for the focuser that is 4x more expensive.

 

I agree with Dr. Ski, when you are at high magnification the last thing you want is a stiff action making your target do the twist in your eyepiece. I'm an AZ type of guy so under these conditions I need/want a focuser that is precise and smooth, one that eliminates the jitterbug in the eyepiece as the target is moving pretty fast. I need/want precise focusing and quickly so I can get on with observing. And I also need/want a focuser that will stay put once focused as I tend to 'steer' with the diagonal. When a rack-n-pinion or a crayford are machined to high quality standards the crayford is less costly to fabricate due to the fact that there are no 'teeth' that need precision cutting. However, a good crayford will have a hard polished steel axle to match/mate with a hard polished steel plate. If the focuser is going to be used with very heavy loads I prefer the best rack-n-pinion I can afford. Otherwise I'm fine with the best crayford I can afford. I use my equipment and consider them my tools of my trade. I don't want to swap gear out regularly that is failing so I save and try and get the very best I can. Something that will last. Purchase once then use and enjoy.

Peace...

 

They seem to be more "mandatory" with faster scopes, which at least in my experience are much more sensitive to focus and require more fiddling. Once you get to f/10 or so, I've never really had a scope where rough focusing was a big problem. Its one reason why I like old-fashioned long ratio achromats. It also depends, I suppose, on the scope - a feather touch is something like 400 bucks? I personally find it hard to justify spending more then 4 times what I spent on an OTA on a focuser (I picked up a used 102MM F/10 achromat for under 100 bucks), especially because I don't do any astrophotography work. It also serves as my primary outreach scope, so I imagine at some point in time the stock focuser is going to get damaged so I'll have to upgrade anyways.

 

I think sometimes a FeatherTouch just seems to fit better..... (aveman

 

@ Diogenes...

I wouldn't be looking at Feather Touch either in your case with the 102. A GSO or similar is where I would try to find a focuser. I have an ES AR127 that I consider a mass produced scope. The glass is good, above average but not exceptional. The focuser is the weak link. When it finally fails if I'm not able to rebuild it I wouldn't consider a Feather Touch or a MoonLite for it. Maybe a used MoonLite if available but not a new one. Maybe when/if that day comes ES will have a better focuser in stock and I can just get one from them. Or perhaps GSO will have something too.

Peace...

 

Thanks, for making my point, Clint Give us a rough estimate of the cost of all the equipment shown in your photo (+/- a couple thousand dollars).
George, you are asking a valid question. Allow me to pontificate.
The rack and pinion focuser on my ST80 is not very smooth. But, the sweet spot for that scope is 12-27x. I seldom go above 50x. No problem achieving focus. Why would I spend more for a focuser than the scope cost. That would be madness.
On the other hand, I have an old ST90 with surprisingly good optics (it was made in Taiwan). Living in the jungle, I have many nights with steady seeing. Also, the ecliptic is very high in altitude. So, I often crank the mag up to 175x to view the moon. planets and double stars. The focuser is a pain in the bee-hind. I will replace it with a GSO focuser. I'm not going to spend $400 for a better focuser. That would be madness.
Any good scope, regardless of being mass produced, will have a good focuser. Why would you want to swap that out? That would be madness.
I am on this site because I'm hoping that like Agena, it will cater to those who wish to enjoy the pure aesthetics of visual astronomy without significant financial investment. There are many demagogues out there who will have you believe that you are missing out on a religious experience if you don't buy expensive equipment. I hate to see people starting out on this venture to be discouraged by technical jargon. I am only a Semiconductor Physicist, but I do have experience in optics and mechanics. And I myself get a migraine after spending 10min reading posts on some of the other Astronomy forums!
Keep it simple and enjoy what the celestial sphere has to offer.

 

I replaced the focuser on my 9.25 SCT with a Feathertouch and glad I did. A very simple job that took 10 minutes and now the beast focuses very very nicely.

I also had a grab n go SW120ST. I replaced the focuser with a Skywatcher 10:1 on that but found if I wanted to attached a DSLR I needed an extra spacer to get focus.

 

I'm later going to replace my meade AR6 and the xt8 with a GSO fucoser. The c102 I can live with the stock. My xt8 is a very early one. I've reworked all of them, but on the aforementioned two, they still have a bit to be desired. The adapters for the Meade ar6 are getting hard to come by though, and I don't think Agena is stocking them anymore. I missed an entire setup (focuser with adapter) about two weeks ago, and now couldn't buy it anyway. I hope I CAN find one later.

 

I have replaced all the Rack & Pinion focusers on my scopes with GSO Crayford's. The 10:1 Dual-Focuser on as many where possible - with the exception being my 200mm F/4 Rich-Field Newtonian Reflector - and this as the only available GSO Crayford for this is single-focus in 1.25" format. I didn't think performing major-surgery on the OTA would be practical for this - but the single-focus was light-year's better!

I've found the GSO Crayfords' to be wonderful! I've used Moonlight and FeatherTouch-Focuser's before, and I found the GSO Crayford's to be about as good. And at a fraction of the price. Which is why I went the way I did - and would again in a heart-beat! As for MoonLight-Focuser's, they do have the dubious benefit of adding the 'Bling Factor' to your scope - as they come in very shiny anodized, neon-colors. If you have deep-pockets - go ahead and spend over $500 on your "baby." I'll stick to GSO-Crayford's though - at around $150 per.

GSO used to be capable of making some poor products. These days, they're producing excellent parts & instruments.

I'll leave you with a photo of my little ST80 - decked-out with a GSO-10:1 Dual-Focus Crayford. I love it! Scalpel-sharp fine-tuning of the image in my eyepiece.

Enjoy!

Dave