I recently inherited a nice Orion 10" Dobsonian telescope, but the base had been irreparably damaged. Coincidentally, I'm also going camping this weekend, and someone suggested I bring the telescope along. Thus I needed a base, fast.
The design is simple and based off of the mount that originally came with the base.
4'x4' sheet of something 1/2" thick.
I used expanded PVC foam, but this could easily be made with MDF or something else.
Conveniently, my father fabricates products from sheet plastic for a living, and since I'm lazy, needed this quickly, and don't currently have the means to cut these shapes out, I asked him to laser cut them from whatever he had available. Turns out, this was 1/4" red expanded pvc. Because I needed the pieces to be thicker, he cut every shape out twice and also sent me the solvent required to weld them together.
Here are the profiles for each piece. For scale, the ring is exactly 2' across.
I had the extra first step of solvent welding each of my duplicate pieces together to double the thickness.
I also solvent welded the ring to the base, but this easily could have been screwed instead.
The rest of the base went together by screwing through parts into the edges of other parts. Since I had the through holes laser cut, this was a really fast and straightforward process.
The alt-motion section screwed together:
The alt-section screwed to the az-section:
A view of the bottom. Made sure these screws were nice and flush with the bottom, if not a little countersunk. You can see some holes where I was planning on adding screws, but it turned out to not be necessary at all for stability.
The section above sits and rotates freely in the ringed base created earlier. I was originally going to add a pivot point, but it turned out to be not at all necessary.