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So I ordered some clamshell rings to get away from the 3-point ring setup, and risk of flexure. They say 'TMB' on them and they're real high-quality, so I guess Astro-Tech acquired them in bulk from TMB at some point.

Here's the triplet mounted in the clamshells, with a 7" ADM vixen dovetail screwed in atop the clamshells. Then, two small dovetails clamp to that rail, and they each have the 3-point ADM rings attached. Since the guidescope weighs nearly nothing, I'm not worried as much about flexure with that. With the Parsec, the filter wheel, and the heavy MoonLite on the triplet, I needed rigidity down below.

Lastly, the Losmandy plate the clamshells will attach to arrives tomorrow, hopefully the space between the holes sets up right.

http://www.silvren.com/astrophotography/refractor-piggyback/

Jeff

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And, the final piece of the puzzle came today. The Losmandy main plate. Spacing was perfect. Now to get this in the field and start using it!

http://www.silvren.com/astrophotography/refractor-piggyback/final-s...

Jeff
Jeff, was curious if this your final spacing for ATFF from the Parsec (pic#7)? What's the inside chip distance to the body. I planning on putting my ATFF on my st8300. I have the manual version of your filter wheel so setup is essentially same (distance wise). Thanks,Marc PS that setup looks sweet-have fun.
Yes, the ATFF should be 57mm from the image-plane/CCD chip. In this config I have it at 53.7mm, which is close enough.

If you look very closely I have the little spacer on the front (side with the printing) of the wheel. This spacer comes with the wheel. This is the only way the ATFF will attach/screw-in as otherwise it hits the filters, when they rotate. And, it pushes the ATFF 2 or 3mm further from the chip, which is good in my case.
Very solid looking and a lot going on in a little package...can't wait to see some images from it!
Me too! LOL. If I ever see clear skies again it'll be a shock!
Oh, did you see, they just released a 102mm!
Yea, super nice! Maybe my next scope!
So I sold the SSAG and got a Starlight Xpress Lodestar for guiding with the ST80. I will probably sell the ST80 in favor of an Astro-Tech ED72. Here's the start of the review of the Lodestar:

http://www.silvren.com/blog/?p=610
Very cool Jeff...looks just like a nail clipper! Just kidding. Charlie just picked one of these up too right? Love to hear how it performs.
t
UPDATE! Bought an Astro-Tech AT72ED scope to replace the Orion ST80 shorttube. Came today in the mail, mounted it atop the triplet, and looks good. Here's some pictures:

http://www.silvren.com/blog/?p=623

Jeff
Jeff, I think you should get another Losmandy D top plate and then a ring set for the 72. Then remove the felt, clean off the adhesive residue, cut strips from 0.030" (0.762mm)-thick sheet styrene (available at hobby shops), and affix them to the inside of the rings with super glue.

I did this and my differential flexure dropped to almost nothing.
Thanks Dave - good ideas. I've already got the Losmandy D plate on order for the top.

Good idea about the felt/glue/styrene. It seems pretty rigid right now, but my next logical step would be getting rid of the 3-points indeed.

Jeff

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