Quote:
Originally Posted by multiweb
Yeah everything is bolted. Makes it rigid and square. Focus is via the primary, which is the best way to do it.
Either OAG will be alright. Adapters are ok too as long as they don't narrow the light path. Try to keep the inner diameter of your rig as close as the inner diameter of your exiting baffle tube, right up to the camera sensor. An added benefit is that you can have more light getting in the pick up prism from your OAG. Most adapters to the back cell restrict the diameter to 1"1/4 already. If it's the case bin it and make your own.
The QHY5 will be nice for guiding with a pick up prism. Not sensitive enough for an AO but sufficient for standard guiding. Also it is quite big in diameter so sometime you won't be able to get it down close enough to the main light path and you might need spacers, then the same spacers before your imaging camera to match focus.
Try not to do that. The 12" is a large heavy chunk of glass and will move regardless. Stick with the original design. Bolt everything at the back and focus with the primary. Keep it simple. Save a couple of bobs. No pun intended.  Adding a focuser at the back will introduce an extra point of flexure and weight to the rig. Image close to the zenith. Your primary will always move whether you like it or not. Locking it won't work and will introduce aberrations with temperature gradients. It needs room to breathe.
I did add some fans at the back of my C11 primary cell. I use them only when the air is dry and when it's very hot. Other than that it's best to keep the air inside the scope as "clean" as possible. Don't push in moist air or you'll dew the inside of the corrector and possibly the primary. In QLD I assume you have high humidity. If the inside of your scope is hot and dry then it's better than cooler and moist. It will equalise eventually. May be a very tiny PC fan inside the scope tube aimed at the baffle tube to disrupt the boundary layer on your primary would work better. |
Much appreciate all this advice Marc, Very helpful & will no doubt save me a lot of time finding some of these issues myself, so very valuably feedback mate
Onward & upwards from here by the sounds, , , Personally, I cant wait to getting involved with all the tricky bits, bashing me head against the wall, throwing stuff, and breakin sh-t sometimes, Lol If someone is going to stuff something up - they may aswell stuff it up properly
All the Best & again, all appreciated Marc
