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Nice work
Bojan
Nice neat simple solution.
I have one of these lenses myself, it looks like a 1970's Tamron 400mm f6.3? My first accessory lens purchase as a 15 year old $60.
As a telephoto it was really awful. It had terrible flare. Good life lesson.
That $60 was earned in holiday jobs, cleaning up apartments following completion construction preparing them to be opened for inspection. Windows, sills, walls floors and kitchens and bathrooms.
Many years ago I disassembled the lens. I found one element a negative biconcave lens used as a tele-extender was never polished properly and still had pits in the glass. On reassembly and without that component, the lens flare cleared up fine but of course the focal length changed and won't focus when a camera is attached. That was ok, by that time I had much better 300 & 500mm telephoto lenses. I kept it as I always thought it might make a good finder or guidescope. As I'm sure you know, the barrels are sectioned and can be easily removed and shortened to modify the focus.
A few Q's
How do you focus? It looks like the helical focus on the barrel is locked in place?
It also looks like it might suffer from some flexure mounted on those springs, no problem for a low power finder, but a bigger problem for an autoguider?
How strong is the 3D printer plastic? The front ring doesn't look very thick for a plastic, but I have not seen any 3D printed parts and am unfamiliar with its properties.
How much do the 3D parts cost to print?
Cheers
Joe
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