Piggybacking - how does it all fit together?

[Delboy_Hog]

Good evening folks,

So I'm just trying to piece together the rings of an ED80 with those of an ST80 guide scope - thought I had all the bits that would be needed to piggyback them, but for the life of me I can't figure out how to attach the two sets of rings together!     Am I missing something obvious, or possibly missing an essential piece of kit?!

Many thanks,

Derek

[Uplooker]

Attach the ED80 rings to the longer dovetail. Remove the 1/4 inch UNC screw from the ST80 ring. Screw it in from the inside of the other ED80 ring. You will not need the black tensioning/ locking screw. You will need a similar sized dovetail to the one that came with the ED 80. Using the screws that you have just inserted into the top of the ED80 rings attach the 2nd dovetail to the top of the ED80 rings. You should now have the ED80 rings with a dovetail on the top and the bottom. Now attach the rings to the ST80. Now I can't remember whether the hole spacing on the top dovetail match with the position of the holes in the bottom of the ST80 rings. As far as I can remember there is very little leeway on where the ST80 rings can be positioned along the OTA before they either interfere with the dewshield or focuser. Position them as best as you can. Once done you will find that you will have to drill a new hole in the "top" dovetail that aligns closely with the hole in the bottom of the ST80 ring.  Obviously this mean removing the dovetail from the top of the ED80 rings. This new hole needs to be slightly larger than 1/4 inch. 6.5 or 7mm should be sufficient. It will not need to be threaded. Once drilled, and with both rings of the ED80 open, using the 2 off 1/4" UNC screw through the top dovetail and into the bottom holes of the ST80 rings.

sorry for the garbled description, am on phone. I am also away from home so can't post any pictures, will ad photos at the weekend

[carastro]

I have an aluminium plate with holes drilled in it which I screw to the ED80 rings at the top (remove the DSLR screw and disc).  Then I screw the ST80 rings onto that, as in attached photo:

Carole 

 

[Delboy_Hog]

Thanks Uplooker, thanks Carole - very much appreciated.

Yikes, drilling? It's such a classic combo of scopes you'd have thought someone would have found a way to attach the two without the DIY-ing? Maybe that's just me not being very good at all that kind of thing! I don't actually even have one at the moment - I'll go and pester my next door neighbour to see if I can borrow his!

Still, it'll be worth it once it's all sorted!

Thanks again!

D.

[carastro]

Quote

Yikes, drilling?

Me too, I always have to find some-one with the right tools to help with metal work.  

Carole