Orion Optics 10" alt-azimuth mounted

[John]

This is my Orion Optics 10" F/4.8 Europa Deluxe OTA mounted on the Ambermille Aztech alt-azimuth mount on a CG5 tripod. The top end of the scope is somewhat cluttered but I've just about managed to squeeze the 9x50 RACI finder in next to the Telrad

It's a reasonably portable setup - a bit under 40lbs all up so I can move it around the garden in one piece which is handy as we have a few trees and streetlights to dodge

[Chris H]

Looking good John, there must be some strength in the top of your mount to hold the weight of the scope without a counter balance. What mirror have you got in there? Do you have the Hilux coating?

[russ]

Looks very handy John. It's funny, in the top photo to looks like it wants to topple over. Do you use it with a counterweight bar and weight?

[John]

Thanks Russ and Chris,

I agree that the scope looks unbalanced in certain positions but it's fine on the flat (which my garden is). I am thinking about a counterweight mod for the other arm of the alt-az though as around 10lbs on there makes the motion of both axis that little bit smoother - I often have my Vixen ED102SS on there as "counterweight" actually !.

The mirror is, according to the Zygo analysis document OO supplied with it, 1/6th wave PV, .982 Strehl and it, and the secondary, are Hilux coated. I guess that's a pretty normal mirror for OO but it performs well when properly collimated.

My only gripe with the OTA is that it's got the standard, unventilated, 3-point mirror cell. This does the job well enough but I'd like to add some more ventilation around the primary to speed up cool-down at some point - either that or upgrade it to the OO 9-point CNC cell which is an open back design.

[GazOC]

Very nice John!

FWIW (and IMHO;)) an upgraded mirror cell is the best improvement you can make to a fast Newt.

[John]

Very nice John!

FWIW (and IMHO;)) an upgraded mirror cell is the best improvement you can make to a fast Newt.

Thanks Gaz - OO do a PX upgrade for £75 which might be worth considering - their 9-point cell certainly looks the business and can be fitted with a fan

[GazOC]

Its worth every penny mate. With a 9 point cell you can just do a 10 second tweek on the collimation once an observing session rather than having to do it every time the scope gets a little knock.

[russ]

Rob had the 9 point cell on his SPX200 and it was a work of art......huge improvement on the standard jobby. I would say £75 very well spent indeed.

[John]

Rob had the 9 point cell on his SPX200 and it was a work of art......huge improvement on the standard jobby. I would say £75 very well spent indeed.

I've no problem seeing that this would be a great use of £75

It's going to have to wait a couple of months though - MOT on wifes car + road tax on wifes car + 25th anniversary on 1 June = delay in mirror cell upgrade

[beamish]

An enviable set-up nevertheless John !!!

[part timer]

Lovely set up there.

I know what you mean about the mirror cell though. I used to refer to them as the 'upturned bin lids' as that's what they were best suited to be in my opinion!

The scope it's self must be a killer though. I think when you do get chance to upgrade the mirror cell it'll become a set up which is hard to beat. The great OO mirrors make them good telescopes for both solar system and deep sky, even being short focal ratio.

I did think of getting one myself but there's something of a funding crisis with that project for now!

[beetlejuice]

Hi John

I have been think of getting myself a dob and, as I have a virtually identical mount and tripod to you (teleoptic giro III and a cg5 tripod), this seems the way to go! Do you find it quite steady? A 250mm newt weighs a bit more than my usual c6/m90 combo. Does it handle the weight ok and still be steady? I have the teleoptic counterweight shaft and weights for my Giro and I was thinking of going for broke and getting a 300mm!

Bob

[John]

Hi Bob,

My OO optical tube weighs around 20 lbs which I think is quite light for a 10" F/5ish newtonian. My mount is supposed to have a capacity of around 20lbs on each side and it's as steady as a dobsonian mount is for viewing. The motions would be a bit smoother if and when I fit a 5kg counterweight to the opposite dovetail but it's quite useable as it is.

I would have thought the Giro III would be at least as good from the reports I've read on them.

[Andrew*]

Wow - that looks dangerous! I didn't know those mounts could be quite so tolerant of imbalance. Do you prefer this to the dob mount?

Andrew

[John]

Wow - that looks dangerous! I didn't know those mounts could be quite so tolerant of imbalance. Do you prefer this to the dob mount?

Andrew

It seems to work smoothly despite the imbalance Andrew although 10lb on the other arm makes it even smoother - I'm going to fix up a mod so that I can hang one of my 5kg CG5 counterweights on there. It won't topple even with the 31mm Nagler in the scope, even without the weight.

I find this setup slightly more comfortable than a dob mount because, by slightly extending the tripod, I can get the eyepiece / finders to a relatively non-stooping height - as a tallish lad youself I'm sure you will appreciate that

Otherwise it's as good as a conventional dob mount except I can use it for other scopes as well

[beetlejuice]

Hi John

The Giro III is very smooth. According to the manufacturer it will carry a 22kg scope + counterweight. Seems more than adequate. My present set up doesn't trouble it. I also used it a couple of times with my C9.25 and it weighs about 20lb or more full up and that seemed fine. Only one way to find out!

Bob

[ringz]

I bought a Giro III mount last year and upgraded it to the Pro version with a counterweight bar on a William Optics tripod.

I've just had my OO 10" F4.8 on it with a 7.5Kg counterbalance weight and It was silky smooth to move about and I can't wait to try it on the sky.

I hated using it on my Vixen GPDX because of having to rotate it all the time to get the eyepiece into a usable position. It will get used now

Martyn.

[Macavity]

Just wanted to (re-)mark this as a great idea. Thanks John et al! With room for but my wheelie pillar (and trusty giro III) in my outside store, this seem to have real potential. With the prospect of "future funding", I still have various trepidations re. accommodating a 10" Dob... should it be a skeleton tube etc. The greatest benefit here perhaps is that could get something I don't have to LIFT very far. LOL. What could be nicer than an Orion Europa... <dreams>

[Rossco72]

Looks a great setup John, I bet the views are great.

[orions-knight]

What a gr8 idea. Seeing a 10" OO on a Alt/Az rather than a dob base has made me think. I have an OO 10" E 8th wave+ that sits on a EQ6 Pro and pier and was considering the OO base, but in a field, might not be easy to level. Although levelling is not too much of a issue with a dob. Your Alt/Az + Scope looks really nice. Way 2 go. Thankyou.

OK

[John]

What a gr8 idea. Seeing a 10" OO on a Alt/Az rather than a dob base has made me think. I have an OO 10" E 8th wave+ that sits on a EQ6 Pro and pier and was considering the OO base, but in a field, might not be easy to level. Although levelling is not too much of a issue with a dob. Your Alt/Az + Scope looks really nice. Way 2 go. Thankyou.

OK

My setup works well but it does need to be reasonably level otherwise the scope tends to drift around on the azimuth bearing if I forget to adjust the tension knob on that axis. My observing site is pretty level (patio + lawn) but I'd probably prefer a traditional dob on a definate slope.

Edit: Just realised that I'm talking guff here - of course it's much easier to adust tripod legs to take account of slopes and keep the mount head level - not possible with a conventional dobsonian of course. What was I thinking - doh !.

[orions-knight]

Maybe your right. Having a dob mount also brings the eyepiece down to a more comfortable height. But having a tripod means that with adjustable legs, levelling shouldn't be a problem. Just thought that set up you were displaying looked quite neat and practical, especially as I do have the original tripod that came with the EQ6.

I think in a worse case scenario, on unlevel ground, the tripod must surely come out tops ?

OK

[John]

....I think in a worse case scenario, on unlevel ground, the tripod must surely come out tops ?

OK

I've edited my earlier post as I've just realised that I was talking rubbish

Yes, the tripod is much more versatile.

[orions-knight]

Thought as much. Now I dont know which way to go.

The idea is to move away from GOTO with the scope when I take it out for those one nighters, especially as its (as you know), quite a beast on a GEM. When of course I go away for the long weekenders, then I like the GOTO/scope combination.

Clear skies

OK