[ontheloose]

I am rather new to madcam (and CNC in general). I have been cutting flat surface portions of a model by selecting surface and running "5 axis from boundary curves". I though all was good until looked closely at the toolpath. With a 1.016mm flat drill the toolpath is too close to the edge. (The surface has an edge). If I select both (vertical) surface and flat surface the toolpath changes to cut the vertical part - but still too close (i.e.it will cut into the model). Not sure how related but if the tolerance of the tool is changed from .01 to .001 the toolpath becomes even closer to the edge.
For the moment my workaround is to create a set of profile curves (that are appropriately far from the edges) - but that seems a bit of a convoluted approach.

I hope someone can relieve my ignorance.

[williamsmotower]

Are you cutting on a 5axis machine? If you're using a 3axis machine use 3axis 2d toolpaths. Profile and facing sounds like what you should be using

[ontheloose]

It is a 5 axis machine though most of our cuts use only 3 axis toolpaths. Indeed perhaps there is a alternate method that I could/should use. But I still do not understand - I though with surface selected and boundary curves at the edges the tool would never go over surface edge. But it is. And changing tolerance effects how much over (tighter tolerance increases the cut "off" the surface)