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8 Inch Reflector on a tracking mount?

Started by kd4avp_1, 10/27/2006 06:17PM
Posted 10/27/2006 06:17PM Opening Post
I would like to pose a question to the group. I have an 8 inch OTA that was on a dobsonian mount at one time. Would it be feasible or even reasonable to mount this OTA on some type of tracking mount? I have been wanting a tracking scope, but I admit funds are limited and I have this OTA already. This OTA is the same one used on the Orion XT8 dobs. What type of mount would it take to do the job? Can it even be done and work properly? I could even build a Dob mount for it and use it in both fashions.
Thanks for any and all input.

Posted 10/27/2006 07:30PM #1
There's a thread on some Forum around here where Rob is asking whether he can mount a 12.5 inch newt on a GEM. Find it and follow. SOme of the same issues will come up. The most important is that the mirror cell design must be able to accommodate the movement of the mount. If you are talking German Equatorial, than some mirror cell designs would be unacceptable.

It sounds like you have a tube with no mount at all, not even a Dob. If so, you might want to build yourself a rocker box and bearings, and just use it as a non-tracking scipe while you figure out a tracking platform for it.

Any GEM you get would have to be pretty hefty. Not only is an eight inch newt tube heavier than most of these were designed to handle, but it is also larger, thus creating more wind load and such.

By the way, I use a 10 inch Newt on my GEm regularly, so there is no reason it cannot be done. You just have to engineer everything right.

Good luck.

Alex
Posted 10/27/2006 07:51PM #2
You can track with a dob. See Tracking platforms (usually a few for sale here as well as a vendor or two)- that would probably be the easiest. Also, you can pick up for fairly short $$ something like an old Meade Starfinder / Deep Space series mount.
Posted 10/28/2006 02:43PM #3
Thanks to all who replied to my question. The OTA I have is actually an Orion XT8 tube. I could easily drop it on a dob mount again and use it. I just have a want for a tracking scope which I dont presently own. I guess its the tinker part in me coming out trying to make a use for something I already own. I like the idea of the Starfinder mounts. I can store this in my outbuilding easily and place on my pad when I get it poured this spring. Cost is a factor, so I will approach it with that in mind. I will try to document it and post images as I procede.
Thanks!
Posted 10/28/2006 04:43PM #4
I realize that I sound like a broken record on this issue but if low price is an issue I would suggest you consider an LXD55 mount. Most people selling on Astromart want the "new" price for their CG-5 or LXD75 ($500 and up). You can find a used LXD55 with Autostar for about $300. Sure it's not a high end astrophotography setup but your post suggest you want a cheap solution.

I'm going on two years with my LXD55 mounts and they work just great with my 8" f6 Newt, 7" UHTC Mak and 102 ED. I did add a heavy duty field tripod (2" legs) to the mount that holds the refractor and Mak but only because dampening time was over 3 seconds with the old tripod extended. You will most likely have your legs collapsed using your Newt and in that configuration dampening is about a second or two.

Jerry

p.s. the shot attached shows an assortment of my low tech scopes.

Attached Image:

SocalDarkSkies's attachment for post 108559