3D printed OTAs

3D printed OTA

This project is replacing the concrete tube OTAs (my tubeless Newtonians) with 3D printed OTAs.  Each requires a mirror end, Focuser end, and two rings in the middle to stiffen the tube and connect to the mount.  I bought a Creality CR10 3D printer which has a work surface of 300mm x 300 mm and a height of 400 mm (12"x12"x16") to print these for an 8" scope.  Print times were  11 hours for the rings, 42 hours for the mirror end, and 47 hours for the focuser end.

Note that the mirror mount and secondary spider and focuser hole are built into the OTA.  Mounting holes for the electrical conduits are also included are are the mount holes for the mount.  This insures that the mirror and secondary are perfectly centered, and the focuser should be perfectly perpendicular.  Since all the rings are exactly the same diameter there should be very little stress for twisting on the conduits.  I am now working on the secondary mirror mount.