Pierce in the middle of the cutout, as far from the edges as possible. If kerf data is present the pierce point on the path is offset from the center by the kerf radius, so that when the machine applies kerf offset it is forced back to the center, thus the leadin on a hole is not generally a radius but slightly angled.
 Raw Path |
 Showing Kerf Offset and Pierce Allowance |
Why Pierce in the middle?
When cutting small cutouts, the arc can be disturbed if it runs over top-surface dross from piercing. We pierce in the middle of the cut, as far from the cut path as possible to minimize the chance of this happening.
This is only effective when TLS is Standard, and when the hole is "small" as defined by Handling Of Drop Cuts.
It can apply to any small cutout, not just round holes. Note the L-shaped cutout on the left, this will probably need a small leadout or some OverCut in order to sever completely, something that would not have been obvious with Show Kerf & Pierce turned on
