The Advantages of Having a Lathe

The Advantages of Having a Lathe

I think I mentioned previously that the Chromacor is a very cool gadget that turns a so-so achromatic refractor into a well-corrected apochromat--but that because the Chromacor screws into the threaded barrel of diagonal assembly on the refractor, there's no way to use the Chromacor without the diagonal in place. This is a problem, because the diagonal adds several inches to the optical path, making it impossible for me to attach my camera to the telescope without removing the diagonal--and thus, the Chromacor.

I decided to fix this, so I turned a piece of Delrin that replaces the diagonal. Since the 48mm threads are not a common tap (and I don't have a thread cutting attachment for the lathe), I bored out the interior end of the Delrin so that I can press fit a 48mm threaded filter in place. (I'll epoxy it in place for permanence.) Now I can screw the Chromacor onto the filter, and put it into the telescope without the diagonal. I now have the advantages of the Chromacor with the option of astrophotography!

I didn't have a big enough piece of aluminum lying about; perhaps I'm look into making them out of aluminum for the ultimate niche market--Chromacor owners!