Yeah, hang on a second, I’ll have to fire up the machine again to do a screen capture…
Okay, here you go - I use a couple of cuts that I know are square, butt them up level against the front of the machine, and then I’m sure that the little item I’m working on is square. (And also closer to the center, which helps with placement.)
The little bamboo bead shown has a slightly curved surface and it engraved just fine.