I’m mostly just venting here, I wasn’t watching right as the cut got messed up so I’m left unsure what happened. The board came loose during the cut but I think it came loose because it tried to do a lead in at full depth. The second issue I see is it clipped the corner but I suspect that occured because the piece had shifted. What’s strange is I don’t have leads turned on for that section, I have a ramp but the erroneous cut isn’t ramped. So, sigh. Going to isolate that part of the cut and try and air cut to spot what might have happened, and I’ll turn off the ramps for now.
I think what happened here is my walnut from Rockler was a bit thicker than usual, at .79" instead of .75". My C3D cutter only handles up to .75" cutting depth and I think the pressure placed on the piece ended up knocking the piece loose. If that isn’t what happened it’s still a concern.
Always measure stock before cutting — added a note to that effect at: https://www.shapeoko.com/wiki/index.php/Operating_Checklist and will add it to the official one.
Oh I measured it. And I’ve cut slightly oversized before but when I line up the bit with the stock this is just thick enough that it may be missing the cutter threads on the final full depth pass.