My first run of keycap casting was a partial success, partial failure. I forgot my pointy tool to get the air out of the keycap stems so there was a big bubble instead of a stem. Other than that they formed really nicely! Some very minimal bubbles on the outer edge of the top but the form and texture look great.
Second attempt at polyurethane casting was a success! The keys are fully formed and the outsides have no bubbles.
They even fit fine on my keyboard, although one is a little looser than the other. It's clear that this resin isn't black, just a dark grey.
The working time of about 7 minutes turns out to be accurate, which is about right for the 4 moulds I have. They seemed to need the full 1 hour cure time, at the minimum demould time of 30 minutes they were a bit too flexible.
The full keyboard is getting there though! Some of the caps are a little loose so I had to put some tape underneath. It makes the fit of the stem a little tighter (hopefully without breaking the stem)
It's very tedious with only two moulds, and I'm out of silicone to make more. This is definitely making me want to get a resin 3D printer to make some custom shaped ones.
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