I got a 6", thick walled cardboard shipping tube from work and couldn't help but see mirrors inside of it. I rescued from the trash and ordered a 4" spherical primary from Sheldon Faworski, and and eBay .866" secondary.
I am taking this build just a tad further on the DIY end as this time I will be building my own spider and focuser, whereas I simply adapted these existing components on my 8". (Who knows, maybe my 3rd project I will try and make a mirror.....)
I am starting out with the focuser. Not breaking ground here. I read Pierre Lemay's page on DIY helical focusers, then put my own spin on it.
The draw tube will be pvc. The base will be 3d printed in pla (at least to start, but maybe permanently), and the bearing posts turned on the lathe from 1/4-20 bolts or rod. A few details not pictured (#4 screws to retain the bearings, but allow removal, the pressure set screw), but you get the idea. The posts are set at 2.5 degrees. I am hoping my printer can accurately enough produce that slant on the holes so the tap can follow. Hopefully I can work on this a bit tonight!
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Edited by nstiesi, 16 July 2019 - 11:57 AM.