Piggybacking

[NickMorris]

Dear All,

I have my eye on a 80mm refractor to go on top of my 8" LX200R GPS and have a few questions:-

1) What is the best mounting solution to give me the least amount of flexure?

2) Could I attach a Canon EOS-350D to the back of the 80mm with this mounting solution without flexing.

3) Can the LX200R be used with a focal reducer as a guidescope to the 80mm?

Thanks for any help,

photonboy

[Ben Ritchie]

I used the ADM rails to piggyback an 80mm refractor on my LX200, which worked very well - remember you need to put counterweights underneath the OTA too to balance the 'scope on top.

You can guide with the LX200, but mirror flop may be an issue. Also, unless you're on a wedge you'll be limited to fairly short exposures due to field rotation in Alt-Az.

[NickMorris]

Cheers Ben,

I have a wedge so all good. Which version of the ADM rails did you get, they seem to have MDS, Losmandy and Vixen?

Which counterweight system did you also go for?

If I focus and then lock the mirror, would this work?

thanks again,

photonboy

[Ben Ritchie]

I had something similar to

ADM Guidescope Rings and systems - ADM Mini Dovetail System with Guidescope Rings

for the 'scope and then this

ADM Guidescope Rings and systems - ADM Mini Dovetail Counterweight Kit

for counterweights. Going back five years, so might have been slightly different and I ordered direct from Anthony in the states as nobody over here stocked it back then. Seem to remember that I had a pair of 3.5lb weights underneath to balance everything. At $2 to the pound the price was somewhat easier to take...

With my LX200 mirror lock helped, but wasn't perfect - not sure if the 'R' is better in this respect or not. I eventually became frustrated with my LX200's tracking/guiding (for a variety of reasons) and moved on to a G11, which just provided a whole new set of problems

[NickMorris]

Cheers Ben,

It looks like the Losmandy version is a much wider rail. Do you think this will have less flex bearing in mind a DSLR will hang off the back?

cheers

photonboy

[Ben Ritchie]

Not sure - might be best to talk to FLO to see what they think, as they might have them to hand. I use Losmandy for everything these days, but don't recall any issues with the narrower rail.