[protoserge]

If it's thin as aluminum foil, it is likely just the variation in the material wall thickness. As suggested, machine to a lower depth.

I wouldn't be too worried about the thin layer if it happens again. Poke it with a punch and run a deburring tool to trim the leftover and you'll be fine.

Edit: I missed the bottom height offset. That will work as well.

Now, test out some higher speeds and feeds and post some videos of the tests!