Nikon ProStaff 10x25 Binoculars Eye Cover and Adjustment Ring

Background

An old coworker told me the adjustment ring for the binoculars eye piece, which helps with focusing, broke and asked if it was possible to 3D print a replacement. Apparently when he contacted Nikon if they had replacements, he was told “no” and that the only way to get the part he needed was to buy a new (as of writing, $110) binoculars.

Some modeling in Fusion 360 and conveniently never returning the binoculars… I finally got the designs done and printed.

Print Settings

• Adjustment Ring: 0.15mm layer height. It's all perimeters so infill isn't a concern. Use a filament with a bit of flex like PETG or ABS, as there's a locking element that requires the flex. Also remember that if you're using this outdoors, something like PLA will probably warp. The higher temps of PETG, and certainly ABS, will be better.
• Eye Cover: 0.2mm layer height. 15% infill or more if you want them stiffer. TPU so it will wrap around the adjustment ring and won't be harsh against the face.

Install

There are 3 small screws that fit into the channels of the adjustment ring. Unscrew them, remove the old ring, install the new one, screw the 3 screws back in. Cover with the Eye Cover.