GSO Telescopes, anyone used them?

[toryglen-boy]

Howdy, anyone here got any practical experience of using GSO Dobs? the 12" looks great for the price, but i have heard they are a bit of a pig in a poke, and you might get a great mirror, or a really naff one,

I know people here, must have used them, and have some practical experiences to share.

ta

:)

[glend]

I had a 12" GSO dob and it was a great scope, the only reason I sold it was because I bought its big brother the GSO 16" Strut Dob which I still have. Both of those scopes had/have great mirrors. Don't be put off be the inevitable knockers who have never owned one. From a value for money point of view they are great. GSO mirrors are surprisingly good, and I recently used one in a 10" imaging newt I built. The scopes are fairly heavy but a 12" can be easily moved around with a trolley. The solid tube 12" can fit in a car to travel to a dark site but it's a bit awkward to handle. If portability is important the sectional dobs might be better for you.

[Shiraz]

+1 - I have now used 4 GSO mirrors (6, 8, 10 and 12 inch) and all good optically. As with any optics, there is always the chance that you will get one that is below par, but I think that the odds are much more on your side than some seem to think. Mechanically the scopes leave a bit to be desired, but you can easily tidy that up a bit. The 12 inch Dob really needs a grab handle of some sort - it is awkward.

[N1]

I have used two 10" and one 8" GSO dobs, one of the 10"s being my own. Whenever I look through them, I think what increadibly good value these things are. They are great fun and allow abolute hours of deep sky observing without getting bored or running out of targets. Mirror-wise - I've so far had both the 10" and the 8" operating at around 350x a few times - that being what the atmosphere allowed at the time. The view was nice and sharp during phases of good seeing. Coma is more noticeable on the 10" as it's an f/5, where the f/6 8" is more relaxed. But the coma doesn't really bother me that much, because I'm aware of the limitations of a newt when it somes to star images in general. (I also have an apo so I know what a star looks like in an ideal world).

The 2-speed Crayfords on the modern GSOs are particularly good, although I've heard of some failing.

Both the 10" and 8" OTAs fit across the back seat of my car (one at a time obviously).

I have not seen the 12" in action yet, but going by the others, it's probably a winner too.

Having said that, it's all anecdotal evidence Duncan, which is of limited use, especially when it's positive. Any negative reports should be more valuable because they would confirm your concerns. (http://en.wikipedia.org/wiki/Falsifiability#Inductive_categorica l_inference) :P

Speaking of which - there were a few minor things I didn't like all that much:

- the secondary collimation screws ex factory (philips head) are just a pain. Replace with knurled knobs such as the ones Bintel sells.

- The primary collimation "lock" screws are in a strange position to act as such (evenly spaced between the actual collimation screws instead of near them)

- Observing height can be a bit awkward depending on the target as with any medium size dob, so that's not actually a GSO specific problem. If anything the 12" should be a bit better here.

[barx1963]

I had the 12" for a few years. For the $$$ a great scope. The mirror on mine was fine. Only real issue was the collimation knobs but I understand the primary knobs are much better. The springs were a bit under powered also.
I replaced the primary, secondary and springs with Bobs Knobs and was very happy with that!

Malcolm

[CJ]

I went from an 8" GSO Dob to a used 10" Orion Dob. The finderscope on the GSO was an RACI scope whereas the Orion has a non standard straight through. The GSO's RACI was much easier to use. The 10:1 focuser on the GSO was nice too. The Orion doesn't have that higher ratio.
But, everything about about the Orion feels more solidly built. The base feels more dense. I don't Know if it's mdf rather than the GSO's chipboard. The various thumb screws are chrome plated steel. On the GSO they are aluminium. Optically, I think comparing an 8" to a 10" isn't comparing like with like, and I don't have the experience or expertise, so I'm not going to try.

The GSO was cheap, worked well and it had good features.
But it did feel a bit cheap.

[rustigsmed]

hi Duncan,

I've got a 12" GSO imaging newt and a 12" skywatcher goto dob. The GSO must have the springs replaced the standard ones do nothing.

My view is the skywatcher has an all round better quality finish (no springs required for replacement), primary collimation knobs better and less flimsy spider vane. still need to replace secondary collimation screws. These things of course can be 'fixed' on the GSO.

Cheers

Russ

[inertia8]

I've used a GSO Bintel 8" Dob as part of a loan program from the ASV. I found it to be great; easily portable, quick to setup and use.

From this experience, I would be happy to get an 8" or 10" GSO. The Skywatchers and Orions, I've not looked through, but would also get one due to the glowing reports on here, it just depends if any turn up in the classifieds from aperture hungry sellers.

One thing I'm not sure on is the focusers, the GSO on the load dob was rather nice to use with the 2 speeds (a larger knob is available to fit over the 10:1 for even finer adjustments) and brass compression rings included on the 2" and the 1.25" adaptor.

I know the focuser on the SW's are a single speed crayford but I'm not sure if they have compression rings for the 2" and 1.25" adaptors as I've read Saxon users report they just have grub screws... might just be a way that they cheapen the saxons for the price point below SW?

Interesting that CJ reports a single speed on the Orion, I presume an older model because they are currently advertised with a 2 speed 11:1 crayford.

EDIT: The Orion XT10 comes with single speed, the XT10g gets the 11:1 from a quick websearch.

[glend]

There was a period when some GSO dobs had weak primary mirror springs, and this was easily fixed by a trip to Bunnings. However, I believe GSO has addressed this with the latest models. The dual speed Crayford style focusers are first class, not as pretty as a Moonlight, or as lightweight, but they are strong and do the job well. The Alt and Az bearings are much better than many competitor dobs (needle roller bearings between steel plates on the Az bearing, and proper roller bearings in the ALt hubs which have tension braking. The tubes balance can be shifted on its axis so you don't have to add weight to the tube that you have to do with some other dobs. Re the bases, they are pressed chipboard and heavy, this is a potential weakness. When I got my 16" GSO I only used the production base as a template for a 3/4" marine plywood base, which is stronger, lighter, and waterproof. You can reuse the needle bearings, centre bolts etc. If you can use a jig saw you can make a base. Bunnings has excellent cabinet making fittings to you can even construct a knock down flat pack version (like mine). So as a basic platform the GSO dobs are a great starting point, add some mods (fan shroud, tube baffle ring) put on some setting circles or add digital encoders and go to full push-to system with Astro Devices Nexus wifi connection to Sky Safari Pro and you have a high end performer. Add on ServoCat and you have full a full goto system.

[N1]

I can confirm that the springs are not a problem on later models. If their job is to hold collimation, they do it well (http://upload.wikimedia.org/wikipedia/commons/6/64/French_Railway_Gun_27627u.jpg).

The base has seen a lot of moisture on mine - no problems so far.

[toryglen-boy]

many thanks to everyone for your input :)

[CJ]

No rubbishy 10:1 for them! I reckon they've been watching Spinal Tap! :D

https://www.youtube.com/watch?v=KOO5S4vxi0o