I'm looking to mount a Meade 12" OTA & a SW ED80 on a Losmandy Titan mount. My preference is to go with a DSBS arangement (using a Robin Cassidy kit) but I've heard that flexure can be an issue with DSBS.
Does anyone have experience with the Robin Cassidy DSBS setup? Would you expect flexure or should I be going piggyback?
I will shed my limited experience here from my own experience of Cassidy SBS setup. They are probably the best SBS setup I have tried (I tried Statstuff & ADM). quality, look & feel are much better than the rest i have tried. Starstuff side by side had one feature which i really liked where I could slide the scope individually horizontally. This feature is probably just unique to Starstuff set up.
All SBS needs perfect balance. if not balanced properly you will get drift which will give the impression of flex. If you have perm setup than you only need to do it once but if you are like me with out a perm setup than you need to do it everytime you setup. You don want to slightly miss balance and later find that star is drifting in main slightly between exposure to exposure.
I found SBS harder to balance compared to mount on top. but once balanced it gave me better result compared to mounting on Top (less pron to wind, need lesser counter weight)
i never use SBS with my lighter setup, because weight of SBS will overweight any additional gain (eg imaging with ED80 & ST80!)
I do use SBS when i use my hevier setup of 10" reflector with ED80.
Thanks for the info sadia. I will be housing the setup in a permament obs (that's the plan anyway) so based on what you say, SBS is probably the way to go. If it doesn't work out, I guess it's not a lot of work to go from SBS to piggyback as I'll have most of the equipment anyway.
Cheers
Matt
With a mount like the titan, I would definitely piggyback the ED80 on top of the 12" and save yourself money and hassle.. Find a way of hard bolting the ED80 on to the 12" with as few moving parts as possible.. I've seen LX200 mounts carrying 12" SCT's and ED80's piggybacked, if the LX200 can do it, the titan could do it in a blizzard..
I found when using a side by side bar with my C11 and ST80 that it was sometimes very difficult to get balance right, and even when you did get it right, there was always an element of movement in something somewhere that caused continuous frustration.. Eventually I gave up on that and went to a piggyback arrangement with a smaller refractor and my results improved... Overall though, if you intend to image through the 12", I would strongly recommend an off axis guider and a VERY sensitive guide camera... That is the best way to achieve good photographic results at long focal lengths, especially in scopes with moving mirrors..
