Back in 2018 I had a smartwatch from Motorola, but the case broke where the strap connects to the case. This rendered it entirely useless, because there was no mechanically strong way to fix that point of the case. I noticed that models released after my watch had a different design for the strap attachment, probably due to this particular failure.
I didn’t want to lose the watch just because the strap bar didn’t work. So I set out to fix the problem with my CNC machine, and a bit of scrap aluminum stock. First I got to work in Fusion 360 and made some measurements of the watch.
Then I set up the CAM for these to be milled out:
After milling, a couple holes needed to be added for the watch button, nuts, and screws. Here is the result after assembling with some copper strap bars I made from 18 gauge wire:
