Andrew Zonenberg on Nostr: I could have stopped to image as the ring of copper shrunk inward, but I had good ...

I could have stopped to image as the ring of copper shrunk inward, but I had good enough views through the soldermask that I didn't bother.

Here's the next pass, with metal 4 fully uncovered and the edge of metal 3 polished away. We can see metal 2 and even 1 coming into view around the very corners.

I want to experiment with using the mill for substrate thinning and see if this might avoid the edge rounding issue (assuming the substrate itself isn't warped). I'd likely still have to sand the last little bit, but it might be an improvement? I'll run a test of that later.