Skymax 180 - Dovetail attachment

[Siegfried1969]

Hello All,

I am considering purchasing a new planetary and lunar telescope. My current telescope is a Russian TAL-1 110 mm Newtonian. I bought this telescope in 2003 and used it ever since. Now for a new telescope, my interest goes mainly towards a Skymax 180 and a Classical Cassegrain 8 inch. For a mount I am thinking of a Skywatcher EQ6 R pro or a AZ-EQ6.

Now with regard to the Skymax 180 I keep reading remarks from people in forums and on YouTube that the telescope, which has a considerable weight to it, is attached on the Vixen dovetail bar with only two small screws. I think personally that Skywatcher know what they are doing and if they sell it like this, that mean it's more than adequate enough but as I keep reading these remarks, I am not entirely confident. Therefore, I would like to ask for those of you who have or had a Skymax 180, if the attachment to the dovetail has ever caused any issue. Especially with an ALT-AZ mounting where the full weight is coming on those two screws. The point is, investing in a heavy mount like the EQ6 to have a maximum stability does not make much sense if the attachment to the dovetail would cause instability. The Classical Cassegrain looks much more robust in that department. 

Thanks a lot and Best Regards !

siegfried

 

 

 

[Nik271]

I use the Skymax 180 regularly on EQ5 and the dovetail has never caused any trouble. The tube itself is steel rather than aluminum, 1.6mm thick so it should be able to bear the weight easily. This is one reason why the Skymax is so heavy (just under 8 kilos).

I don't have the CC8, it has some very good reviews. It does seem to be more rebustly designed and a bit bulkier. Any of these scopes will sit on EQ6 with ease.

The main drawback of the big Mak Casses is thermal equilibrium, best stored in an unheated observatory or shed. The CC8 is more readily deployable.

[wookie1965]

Just going to say my friend has the 180 pro with a RACi and binoviewers and says its very solid.

[M40]

Mine has all the usual bits and bobs fitted including the steeltrack focuser and motor and never had a concern over the strength of the dovetail bar. I keep mine in an unheated garage so by the time I have bolted it to the mount, stuck all the stuff on it and then polar aligned it's good to go but if you are keeping yours inside I would also consider the Classical Cassegrain.  Binoviewers? yes please, defo on the wish list.

[GazOC]

I've had mine for 15 years or so now on an HEQ5 mount with no problems 

[Captain Scarlet]

I too have a Skymax 180 and have had it completely apart on several occasions (see here) The dovetail attachment is very solid, and there is no discernible sag in use.

Magnus

[nfotis]

I doubt that Skywatcher don't know what they are doing. I own the Skymax 180, even used it with an old HEQ5 mount with the small saddle. No problems so far.

If you want to load it heavily with accessories, a larger saddle should help. There's also the option to add tube rings etc, if you feel it necessary.

Celestron offers a version with a wide (Losmandy compatible) dovetail, but it's not easy to locate in Europe (and it's costly)

 

N.F.

[GuLinux]

I can join the chorus and confirm I never had any issue with the stability of the plate.

As for the losmandy dovetail, I recently got this from FLO: https://www.firstlightoptics.com/dovetails-saddles-clamps/stellamira-universal-losmandy-style-dovetail-bar.html . I struggled a tiny bit to mount it (there's a couple of washers inside the scope, but they were too narrow for the new bolts) but other than that it's a good fit, and if you want more stability, the design is simple enough to drill extra holes and add a few more bolts (this could be done with the vixen bar as well).

[GazOC]

On 13/10/2022 at 20:15, Captain Scarlet said:

I too have a Skymax 180 and have had it completely apart on several occasions (see here) The dovetail attachment is very solid, and there is no discernible sag in use.

Magnus

Edit: just found the answer while reading through the full (and very informative/ thread 👍

 

That's a great read. Did you happen to measure the height of the primary baffle from the mirror or backplate? I stripped and measured my gold 180mm a couple of years ago (nowhere near as exhaustively as you have) and would be interested to see how that measurement compares as all the other optically important ones seem to match up 

Edited October 16, 2022 by GazOC

[Siegfried1969]

Thanks a lot for all your informative replies! So, as I already assumed, the attachment to the dovetail 'looks' concerning but it is actually not. I did also some research myself and I found out that even a tiny screw can carry a considerable amount of weight (something like 300 kg for a 3 mm screw). The weight of the Skymax is far off from that.

The take apart thread from Magnus is super interesting! In the meantime, I have not yet decided for the Skymax 180 or the CC8. Performance wise, the two scopes are nearly equal (with a slight advantage for the CC8 as reported by most observers) so it comes down on personal preference. 

For the moment, I am leaning more towards a CC8 on a AZ-EQ6. An AZ-EQ5 should probably work as well but as I am used to my TAL-1 for 20 years now that is built like a tank, I do not want to go for something more fragile.

The plan is then to mount my TAL-1 tube on the AZ-EQ6 as well and continue to use it for solar observing. For solar I prefer low magnifications somewhere in the 30x range up to max 90x which these long focal length telescopes cannot deliver.

I am not into astrophotography by any means, but I really like sketching. Planets, sun and moon is what interests me. Not so much deep sky though...

 

[Captain Scarlet]

On 16/10/2022 at 08:14, GazOC said:

Edit: just found the answer while reading through the full (and very informative/ thread 👍

 

That's a great read. Did you happen to measure the height of the primary baffle from the mirror or backplate? I stripped and measured my gold 180mm a couple of years ago (nowhere near as exhaustively as you have) and would be interested to see how that measurement compares as all the other optically important ones seem to match up 

Alas I don’t think I did measure the primary baffle tube. Next time I have it apart I’ll do so.

M

[nfotis]

To the OP:

You may be interested in viewing this video, where the guy modded his Skymax 180, with flocking, rings and rails etc.

 

 

Personally, I watched it at 2x speed and using subtitles because it was a bit slow-moving, but it was quite interesting.

Cheers,

N.F.

 

[nfotis]

And here's another approach in modifying the Skymax 180:

 

 

Personally, I think that I would use an external focuser instead, as the newer copies have an SCT-compatible visual back.

N.F.