I think I am going to try and mount my Sky-Watcher Esprit 120mm with my C11” where I am currently using a piggyback design with an 80 mm. My set up requires it to be in park 4 in my ROR observatory for it to close. I understand that side by side is a better design. Any recommendations on the best side by side mounting plate to use?
I use the SBD18SS that AP sells, riding in a DOVELM162, with a C14 on one side in another DOVELM162, and a 6”f9 on the other side in an ADM TGAD, for which I made a custom riser plate. I’ve thought about replacing the TGAD with another DOVELM16, and shimming to get collimation, but the flexure in the TGAD has been acceptable for my visual use.
I switched from piggyback to tandem arrangements for all of my imaging and guide scope combinations hoping that doing so might reduce or eliminate what I believe to be differential flexure in some of my images.
For my tandem arrangement I have a DOVELM162 attached to the Declination top plate on my 1100GTO mount as the base dovetail slide. Then I have a SBD13SS attached to the DOVELM162 base, with another DOVELM162 to which the imaging scope is attached, and a DOVEDV10 for the guide scope. The sketch below shows the arrangement with the dimensions that balance the arrangement for my 180 EDT setup.
Although I did not see any significant reduction in the differential flexure, I did find that the tandem arrangement makes it possible to more precisely balance the scopes. Roland has some good instructions on the A-P web site for balancing a tandem setup. The most important step being to do some or all of this procedure indoors during the daytime so that you can see what you are doing.
