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Designing a 6" single strut planteary Dob

Started by tomrod, 11/16/2002 10:20AM
Posted 11/16/2002 10:20AM Opening Post
I just bought a nice 6" f8 1960's era mirror with cell by Edmund Scientific. I want to make a custom Dob using a bunch of Bosch "erector set" type aluminum extrusions. The main support for the eyepiece would be a very stiff 40" long 1.6" x 1.6" extrusion.

I have a 1" diagonal which is a little small for the mirror. I plan to compensate for this by making a linear focuser that moves the secondary and the mirror up and down rather than moving the eyepiece in and out. This would allow me to put the eyepiece as close to the secondary as possible.

There will be no tube, but a thin ring of fiberglass would provide a dark background for the eyepiece. The spider would be two stainless steel strips attached to a four screw push-pull adjuster. The spider would be fixed, but mirror and cell could be moved left and right to align the optical axis with the focuser travel. The cell has the standard three screw adjustments to align the mirror.

Any comments from those more experienced?

There are only 10 kinds of people who understand binary - those that do and those that don't
Posted 11/19/2002 03:47PM #1
Do post pictures when you finish!