Hi,
Zig-Zag pocketing typically doesn’t need a Lead-In/Out itself.
The mill plunges at the start, retracts at the end, and continues with the next tool path.
(Knowing that it is related to Zig-Zag because I recognize one of my own test shapes)
Mostly because it is a coarse machining cycle.
Chip-load is not controllable for the full path, the mill can even be fully engaged with the material at some places.
Zig-Zag typically switches from Conventional to Climbing what will not produce the same finish.
The best you can do is a ramp-in where there is some forward motion while plunging.
QCAD/CAM doesn’t supports that.
For Laser machining as in your case it is even simpler, the beam is turned on and off.
Lead-In/Out is again something especially for finishing cycles, typically for the final one.
QCAD/CAM doesn’t automatically figures out an ideal place to put the Lead-In/Out.
An open tool-path is processed from begin to end.
A closed tool-path can be processed from any point on the curve and is not necessarily a polyline.
For a polyline the user can force QCAD/CAM to start at the begin of a (closed) polyline.
The user can relocate such a start position (Method OR).
It is never a good idea to add a Lead-In/Out near a sharp corner, at an inner corner or in a tight space.
At best located near a long edge where there is already freed up space to approach the final contour.
There must always be sufficient space or waste material available to allow the Lead-In/Out.
Your proposal doesn’t hold mathematically for every possible situation.
e.g. For pocketing text there is usually no room to do so.
The solution of QCAD/CAM is not faulty … It is the place where it is requested to include.
As last: in QCAD there is no such thing as an ‘enclosed area’ … All is merely Line-Art.
A Hatch is not a filled enclosed area … It is a color fill or a collection of line-art from edge to edge.
Regards,
CVH