So I have a 12.5"/f4.8 mirror with a 2.6" diagonal (out of a Meade Starfinder) and a 2 speed focuser. To complete a dob, I'll need a tube and a box as well as a mirror cell and a spider for the diagonal. Eventually I'll get a poncet platform for it, but right now I'm just stumped as to what kind of tube and mirror cell I ought to use. Any comments or advice appreciated. Never done this before...thx, royjohn
12.5"/f4.8 build advice
Posted 08 May 2021 - 09:56 PM
I'd do a truss and build your own cell
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Posted 08 May 2021 - 10:27 PM
If you are going to be traveling a lot with the 12.5", I agree with above and make it a truss design that you can break down for easy transport. If staying in one place, then a solid tube would be fine and easier to build, keep collimated, etc.
Here are some ideas to build or buy a mirror cell:
Edited by otocycle, 08 May 2021 - 10:30 PM.
Posted 08 May 2021 - 11:00 PM
Have you built any telescope mount before? The Dobsonian mount for a 12-incher is quite doable for a first structure project. And the Poncet Platform can be an add-on later. Just build your scope with that in mind --- that it should tolerate leaning five or even more degrees off plumb without deciding to spin or crash. You could build the platform... but that's rather advanced. Buying one would make more sense, for most of us. Tom
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