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Thread: Diy 12" sct

  1. #41
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    Basically, I knew what the f.l. of the system was to be and divided by three. Then you figure out what the length of the imaging system is that you want to hang on the backside of the scope. In my case I was planning to use my Meade flip mirror box with a t-mount for my camera. Adjust each of the three lengths by subtracting for this extra. The rest of the figuring was purely trial and errror. I used the threads of the PVC fittings to try different positions for the corrector plate. I did have to cut the long tubes 3 times to get near focus. Once you are there then all you have to do is move the main mirror back and forth until you get your prime focus. The moon is great for this purpose. Good luck!
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  2. #42
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    Default Re: Diy 12" sct

    Well, after a substantial hiatus, I am back at the beast. Mirror flop turned out to be a major problem, and real observing time was rare, with all the fiddling required to get around constant changes in collimation of the mirror. The problem was finally solved by getting a large helical focuser from some surplus optics. The focuser has a tube size of 2" and is 5" long with 4" flanges on each end. Total length of travel is 1.5". Just installed it this week and will be reporting further progress as the weather permits. As ever, we are heading for the "June Swoon" in the SF bay area, noted for FOG. Regards to all, Leo.
    C8, CPC8 w/Fastar, 2xQ3.5, 2xLX200 classics, one with 12" Homebrew hardware, Nexstar 4si,6" homebrew/ground Newt, Meade SN10 and a BUNCH of project OTA's.

  3. #43
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    Default Re: Diy 12" sct

    I'm very excited at this point with the new setup, the helical mirror positioner works like a champ with little detectable mirror flop during scope movement and during repositioning of the mirror. System is co-linear and I can move into and out of focus using either the GSO Crayford focuser or the mirror positioner. This is a very solid setup, now.

    HelicalFocuser.jpg
    C8, CPC8 w/Fastar, 2xQ3.5, 2xLX200 classics, one with 12" Homebrew hardware, Nexstar 4si,6" homebrew/ground Newt, Meade SN10 and a BUNCH of project OTA's.

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    Default Re: Diy 12" sct

    Image of Vega after last night's clearing of the clouds, about 10 p.m. PDT.Vega-06112013.jpg
    C8, CPC8 w/Fastar, 2xQ3.5, 2xLX200 classics, one with 12" Homebrew hardware, Nexstar 4si,6" homebrew/ground Newt, Meade SN10 and a BUNCH of project OTA's.

  5. #45
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    Default Re: Diy 12" sct

    Sorry to bump this old thread again, but I have "Finished" the 12". Final changes were to eliminate the plywood, replacing with 0.085" anodized aluminum, eliminate the PVC pipe using carbon fiber and aluminum struts and moving to a smaller 1" square flex-frame material for the basic structure. Upshot of all the changes was to bring in a final weight of 25.5 lbs, easily within the capacity of my LXD-55 mount. Works great, very stiff, easy collimation, cools as fast as the glass cools and very portable. Regards to all who have followed the progress in the past. Anyone wishing to repeat the exercise can email me and I'll be glad to share measurements.DIY-SCT-small.jpg
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    C8, CPC8 w/Fastar, 2xQ3.5, 2xLX200 classics, one with 12" Homebrew hardware, Nexstar 4si,6" homebrew/ground Newt, Meade SN10 and a BUNCH of project OTA's.

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    Default Re: Diy 12" sct

    Wow! Very nice job there! I am impressed.

    Clear Skies!

    Dave

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    Default Re: Diy 12" sct

    That is awesome. I have always wanted those manufacturers to make a truss version of these scopes, looks pretty impressive.
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    Default Re: Diy 12" sct

    Please read the rules about necro posting
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