What equipment choices would you conside to mount 3 scopes on a large enough mount?

[g__day (Matthew)]

I guess you could use a plate and run all three on the plate an attach the plate to the mount via a perpendicular dovetail (the way many folk attach a ED80 and SCT if they don't want to piggy back the ED off the SCT).

But say I want to attach a 9.25 SCT to the mount and want to somehow rigidly attach, align and balance an ED80 and a 5" MAK to the SCT - without overly stressing the SCT tube - what would folk advise?

I guess I'd need the 9.25 to be attached by rings to the dovetail to the mount. Then add extra dovetails and attach to this their own oversized rings with 6 adjustment screws per ring set to align their tubes. And to balance the MAK and the ED80 I probably need the MAK at the 3PM position and the heavier (WO) ED80 at the 11PM or 7PM position.

Any suggestions (other then it will be a mother of an expensive mount that could carry all those scopes - and it would be horrendously expensive to get one with good enough PE to be useful)?

[ballaratdragons (Ken)]

I certainly would be worried about stresses if they were all mounted via the one dovetail.

I would suggest a Bar and parallel dovetail system.

[Kal (Andrew)]

I agree with Ken, I think a parallel dovetail would be a better solution. Apart from being more rigid, it would help to keep the weight of the OTA's closer to the mount head.

[Bassnut (Fred)]

You may be able to mount the 9.25 and 5" to the top of a parallel dovetail, and the ED80 underneath it, to the side, saw that somewhere, looked good. Would keep the counter balance weight down.

[g__day (Matthew)]

A bar may be the only way to go cheaply, but forgo cheap for a moment and what options exist? I remember an issue of UK astronomy in the last two years where a guy mounted about 5 scopes on one incredible mount - I've been hunting that article since to see how it was done.

[Karls48 (Karl)]

What about Giro mount? You can have two scopes counterbalancing each other. Some models can take big payload.
www.handsonoptics.com/mts_giro.html

[g__day (Matthew)]

Er - but it's not the mount that's the focus of this question - its how to align and balance 3 scopes without resorting to a bar if possible!

[ballaratdragons (Ken)]

Originally Posted by g__day

A bar may be the only way to go cheaply, but forgo cheap for a moment and what options exist? I remember an issue of UK astronomy in the last two years where a guy mounted about 5 scopes on one incredible mount - I've been hunting that article since to see how it was done.

In the pics below is how I parallel mounted my wierd set-up to keep the balance just right. Worked well.

I still only used one dovetail mounted 90 degrees out with 2 parallel bars. You would need a solid bar at 90 degrees and two parallel Dovetails. Almost what I've done in the pics but reverse the parts.

I only use the 2 scopes now though, one above the other as weight isn't an issue.

P.S. If you are wondering why I had so many scopes on there, it was so I could do visual observations of the object whilst Imaging and Autoguiding.

[rumples riot]

Dove tail plating is the surest way to remove flexure.

As for Mount I recommend the G11. Peter Miller (Adelaide) has his TOA130 and C9.25 mounted on his G11 and it tracks nicely. The PE is low on those mounts and they are known for their reliability. Or if you want to spend a lot of cash try the EM400.

[g__day (Matthew)]

Ken - where I to go a bar - that is exactly how I do it!

Rumples - agree with you the G11 looks like the best bet in its price range - given the quality of the gears vs the CGE. And yes I love to have the cash for a EM400.

But as a non bar configuration I'm still searching for the attachment components!

[[1ponders] (Paul)]

Dovetail plating is the only way to fly. I can autoguide using an 4" f10 refractor and an 8" meade SCT with np at all on a GM8 using the side by side mount. Yes it is a bit over the limit for photography for that size mount, but it leaves the over and under setup for dead with ease of use in autoguiding.

Balancing it is a learning process in itself though

[g__day (Matthew)]

Paul,

I'm curious now - why does it "leave the over/under set up for dead"? Is it the rigidity of the setup?