Guidescope attachment

[Mr Thingy]

Pretty sure this is a stupid question but I have to be asked as I can't figure this out myself 🤔

I have a SW Evostar 72ED and a Guidestar 50ED that will be the guidescope. I don't want to attach the 50ED using the finderscope shoe as I foresee a scenario involving gravity, the floor and some expensive gear, so I want to mount directly onto the top of 72ED.

However, I can't see how this should be done, so I'm looking for tips. The ED has a dovetail - do I need to replace with a different plate? 

Thanks in advance kind people of greater brain power than my own 😉

[fifeskies]

You can fit guidescope rings to the top of the 72ED rings and piggyback your guidescope.

Also allows far more accurate alignment between the two

 

Depending on spacing you may need to fit a top rail above your scope rings

[Skipper Billy]

One way of doing it is to swap the miniscule dovetail that comes with the ED50 for a longer one that can the be bolted directly to the top of the main scope rings.

See attached - different scopes but same principle.

 

[fifeskies]

Just another photo of a piggyback guidescope to illustrate

 

[Skipper Billy]

I had the same guide scope at one point and found that the adjustable rings it came with were awful in terms of flexure. I made an alloy plate with two stainless steel exhaust clamps and fastened the plate to the top dovetail - the guide scope was protected by slipping silicone tubing over the U bolts - zero flexure!!  Not adjustable but the guide scope doesn't have to point exactly where the imaging scope is pointing.

 

[Mr Thingy]

I thought I was missing something obvious but it looks like just a bit of tinkering is needed. Thanks to all.