I made this case to hold a Meade telescope eyepiece as a test to see how well the threads would work as well as a test of the X/Y calibration of my printer.  It was designed using DesignSpark Mechanical (threads, fillets, and chamfers are easy!).  My printed version fits a little tight, so I opened up the inner diameter by 1mm to make it easier to get the eyepiece in and out of the case.  It will fit the eyepiece whether you have the eye guard extended or collapsed.  It is intended for use with the lens caps in place.I sliced in Cura and printed with Coex3D ABS on Son of MegaMax, my recently rebuilt printer, with a 0.4mm extruder nozzle and 0.32mm layers, 20% infill.  No support, no brim, no raft.