I’ve had my X-Carve for a week or so, been practicing with my favorite material, Corian. Just cutting pieces to get practice with the machine an procedures.

I’ve got a round piece I’ve been trying to cut and tried the 2-stage carving several times but I simply cannot change the bit without moving the carriage at least a little bit, and the X-Y zero in Easel leaves a lot to be desired in terms of precision. Not owning an X-Y-Z probe, I cannot re-zero it to the new bit size well enough to make the finish cut accurately.

So, in this last attempt I decided to just take the time and make the entire cut with the same bit I would have used for the finishing cut, a 1/16" upcut bit.

This was easily the best I’ve had yet, and it turned out great for the first 12 passes or so. When I got the finished piece out though, this is what I found on the bottom (flashlight to show detail):

So in the middle of the piece it’s higher, in a seemingly random shape, and along the edges a clear curved climb can be seen.

Do any of our more experienced cutters have any ideas on what could have caused this?

Bit: 1/16" upcut

Feed rate: 750mm/min

Plunge rate: 200mm/min

Depth per pass: 0.7mm

Final depth inside design: 6mm

Outer circle through-cut with four .5mm tabs

Stepover: 40%

DeWalt 611 spindle

Material: Corian, 8mm thick