Mount a second scope to my Newt

[idlelimey]

Hi All,

I recently bought 3 Meade RB70 refractors (tubes only) for a hobby project. I want to keep one of them and mount it on to my SW Explorer 200 newt. I've seen pictures of similar setups but I can't discern they method they've used.

I think it involves another dovetail and and some more tube rings on to that.

(borrowed from Observatory Dome Project - excellent page also)

The idea is to line it up like the finder scope but to use a 25-32mm EP in there for a constant wide view without the need to keep switching EPs in the primary scope.

Has anybody else done this? Any help on what equipment I'd need greatly appreciated.

Best,

[pritc]

Your sig says you are using a EQ5 mount??

Using a SW200P you have reached max weight advised for that mount.........

To Piggy back another scope you might have to upgrade to a HEQ5 or EQ6.......

Wayne

[Sparrow]

Hi Idlelimey - in answer to your question how do others do it - Mine is very much a "Heath Robinson" affair but it works. I've got the 88mm reflector piggybacked on the 8" Newt on a CG5 mount which handles the weight fine. The two are connected by a piece of aluminium rescued from our old conservatory roof - the reflector is bolted to it, and it is bolted to the available threads on the Newt rings - one of which is the camera piggy back screw. Originally I used a piece of wood but that allowed flex - the aluminium has eliminated that. - Cost £0.00 - lack of money is a great source of inventiveness

I've attached apicture - not great because it doesn;t show the bracket but it should give you an idea

[idlelimey]

Your sig says you are using a EQ5 mount??

Using a SW200P you have reached max weight advised for that mount.........

To Piggy back another scope you might have to upgrade to a HEQ5 or EQ6.......

Wayne

Thanks for the advice Wayne. Given that the mount appears to be bomb-proof I would never have suspected any problem with extra weight. The RB70 weighs very little, would it really cause a problem for the mount?

Appreciate your insight!

[idlelimey]

Hi Idlelimey - in answer to your question how do others do it - Mine is very much a "Heath Robinson" affair but it works. I've got the 88mm reflector piggybacked on the 8" Newt on a CG5 mount which handles the weight fine. The two are connected by a piece of aluminium rescued from our old conservatory roof - the reflector is bolted to it, and it is bolted to the available threads on the Newt rings - one of which is the camera piggy back screw. Originally I used a piece of wood but that allowed flex - the aluminium has eliminated that. - Cost £0.00 - lack of money is a great source of inventiveness

I've attached apicture - not great because it doesn;t show the bracket but it should give you an idea

That could be the coolest thing I've seen. What a rig! There was an ST80 on SnS earlier for ~£75 (OTA only I think). I was very tempted as a portable scope.

[idlelimey]

UPDATE:

Just finished looking in to Wayne's feedback and my EQ5 can handle 9kg apparently! I'll do a full weight check later on but the information I'm getting is that you shouldn't push it to that limit anyway.

I must admit, I'm stunned - the mount is such a hefty unit I would have thought it take a bus and point it in the right direction

[haitch]

Take a look on astroboot for some guide rings then get yourself a piece of metal to join them to your rings.

[idlelimey]

Take a look? I'm never off it! I'm guessing I'd need adjustable rings (more like finder scope rings, with adjustment screws) than straight up clamps.

However, everything hinges on this weight issue.

[pritc]

Earlier SW200P weight discussion

http://stargazerslounge.com/equipment-discussion/95685-skywatcher-200p-tube-weight.html#post1362662

[idlelimey]

Thanks pritc! Just finished weighing in - OTA 9.3kg (inc. rings, dovetail, finder). The counter weights are 10.5kg.

Wishful thinking that I could use up to the total counter weight amount I suppose? The Meade RB70 weighs a fraction over 1kg.

Could I damage the mount by loading up with what would amount to 10.5kg on either side?

A shame as all I actually need for this is another dovetail. I've tried and the scope will Meade will mount to the SW using on dovetail. Downside would be no fine adjustment (as per a finder scope).

The sensible solution would be a new mount but I'm tight and not very sensible.

[haitch]

Thanks pritc! Just finished weighing in - OTA 9.3kg (inc. rings, dovetail, finder). The counter weights are 10.5kg.

Wishful thinking that I could use up to the total counter weight amount I suppose? The Meade RB70 weighs a fraction over 1kg.

Could I damage the mount by loading up with what would amount to 10.5kg on either side?

A shame as all I actually need for this is another dovetail. I've tried and the scope will Meade will mount to the SW using on dovetail. Downside would be no fine adjustment (as per a finder scope).

The sensible solution would be a new mount but I'm tight and not very sensible.

You'll be wanting guidescope rings I guess with the bolts through to adjust scope alignment. The EQ5 mounts are fairly solid - so long as it is well balanced so you don't put too much strain on the gears I wouldn't have thought you'll do too much harm. Keep the legs short to minimise vibration and it may be ok for visual. Are the legs steel or Ali?

I used to have a Meade AR-6 refractor on my CG5 (essentially the same as an EQ5) and except for high magnification, where the motor tick showed up in the view, it was fine. I've just done a google and came up with US weights of 25 and 27lb for it. That's between 11.33kg and 12.25kg (plus diagonal, finder & some weighty EPs) and it had a lot of leverage. You'll have to make your own mind up but I'd be inclined to give it a go (the CG5 did have 2" steel tripod legs which helps with vibration).

[idlelimey]

The mount legs are steel - at least I'm pretty sure they are. I keep them short, despite me being quite tall I've never needed to extend them any.

I think I'm going to give it a go anyway. If it doesn't work then the dovetail will still come in use later on.

I don't have motor drives on my mount but will pay attention to the ease and smooth motion of the RA etc.

£20 for a dovetail seems a bit steep for a lump of aluminium so I'll keep an eye out on Astroboot.