Thanks to Irak for picking up this discussion. It is important and it's a shame it just fizzled out.
IMO chrisb's comment here should be starting point of all further discussion:
https://forum.freecadweb.org/viewtopic. ... 30#p447298
Clamp clearance height would be more explicit and it seems that this was the original intention but if the behaviour was consistent Clearance Height would probably suffice. It maybe part of work-piece we need to avoid hitting, not the clamps. This is Chris' height #3:
3) Height above the clamps. Used to avoid any crashes
The problem comes with "Safe Height" which is anything but safe. This, IMO, needs renaming to reflect what it does. Unfortunately this is not even consistently applied. As I pointed out in my previous comment drilling seems to have taken on a different use of "safe height" than that used by pocket ops. This obviously needs to be used consistently across all Path WB operations. Once we know what it does, we can find suitable name and documentation diagrams can be corrected show how to use it.
Pocket ops retract to "Clearance Height" between each pocket and use "Safe Height" in the sense of Chris' height #1:
1) Height where vertical rapid-down-moves end and motion changes to working speed. This is used so that the tools enter at decent speed into the material
Drilling seems to use "Safe Height" as in the sense of Chris' height #2:
2) Minimum height at which I can move horizontally. This is used e.g. for moves above the surface between clamps and can be used for two adjacent pockets or for drilling operations for several holes if no clamps obstruct the paths between them.
My bold.
It seems that current FreeCAD functionality requires at least these
three heights. .
As I previously stated, it seems that wsk8's "keep tool down" mod could be used to maintain access to current drilling behaviour while removing the inconsistent use of height conventions provided it is
off by default. Both pocket and drilling ops would apply ht #3 and ht #1 , and "keep tool down" would provide a manual over-ride to apply ht #2 between holes and pockets in the same operation.
Making use of BaseGeometry order would allow the user more control in avoiding clamps too:
https://forum.freecadweb.org/viewtopic.php?f=15&t=51900