The left temple mount of Mary’s five-year-old and staggeringly expensive titanium Silhouette glasses snapped. Here’s the intact right earpiece and the broken piece from the left temple (the lens is upside-down on the paper):

They’re just about ideal glasses, with nothing more than two lenses and three metal bits, but that means simple repairs don’t come easily. The Official Repair Price was about $120 to install a whole new earpiece, so, seeing as how she had these customized for computer work and wouldn’t be wearing them when anybody else was around, I got the job…
First off, mask the lenses with Parafilm to avoid scuffs:

Then cut out the broken part shown in the first picture. It’s attached to the lens with a U-shaped bit of transparent plastic that fits into the frame holes and captures its two peg legs; I used flush-cutting pliers to carve away the plastic bar on the inside of the lens.
The lens mount fragment is flat-out not reparable, but the broken end of the earpiece lies flush against the lens and is roughly circular. Even better, a 1/16 inch brass tube from the Little Box o’ Cutoffs fit the temple end perfectly: OD = 62 mils, ID = 35 mils.
The Little Box o’ Tiny Screws produced a pair of stainless steel screws (intended for the hinges in ordinary eyeglass temples) that also fit the holes in the lens and were precisely the right length, so the overall plan came together. The screws seem a bit over 1 mm diameter and I don’t have a nut for them, but epoxy is my co-pilot…
Line up and drill a pair of 47 mil clearance holes in that piece of 62 mil OD brass tubing, leaving barely 7 mil behind on each side:

I may have to frame that picture…
Much to my astonishment, drilling those two holes worked on the first try. I’d chamfered the end with a #1 center drill while mulling over how all this would work out.
File off the screw heads to leave a thin plate:

A dry fit shows how everything hangs together:

The intact earpiece holds the lens at the proper angle on a flat surface, so as long as I can keep the repair parts in place on the lens, the temple angle will take care of itself.
I scuffed up the broken end of the earpiece to encourage a good epoxy bond, bent the edges of those flat plates around the tube, and cleaned everything with acetone. Tiny dabs of JB Weld epoxy hold the screws and the temple piece in the tube, with those little machinist’s squares encouraging the lenses to stay put:

A day later, lay the lenses face down so the screws point straight up and dab on more JB Weld:

Those dots aren’t quite as round as I’d like, but they’re the better part of 2 mm OD and I’m not complaining much. Note the nice fillet around the temple piece at end of the tubing.
Pause another day for curing…
Then file off the rough edges and peel off the Parafilm. It’s a bit on the garish side, but Mary preferred the Steampunk look over a crude paint job, particularly because it’s invisible from her side of the lens:

There, now, that wasn’t so hard after all…
Very nice work, good sir!
And she likes it, too!
Thanks…
Very nice work Ed, I have a pair to fix and this gives me ideas!
We think the earpiece will eventually break free of the brass tube, because the epoxy has little more than faith to grip in there. At that point, using epoxy instead of nuts may look like a Bad Idea, but I don’t know any other way to secure the screws to the lens. Whatever you come up with should be better!
Thanks…