Highlighting minimum external radii for CNC milling

Hi guys,

I’m working with some freeform planar curved shapes that are to be used to cut wooden objects on a CNC milling machine. I am looking for a grasshopper script that can help me find and highlight the areas on the curve where the drill piece will not be able to fit in - i.e. the areas which have an internal radius smaller than the diameter of the drill piece.

Any ideas? Thanks!!

Maybe this dogbone corners definition by Noah Brock can help:

Very simple, here my solution with Clipper Offset (Rhino offset is not very good)


@laurent_delrieu Thanks for the tip - seems to work pretty well for the task at hand. One thing that I am noticing is that the final geomerty doesn’t align perfectly with the original geometry in some places (see image), so I am unable to just bake the final geometry from grasshopper as this gives me a slight missalginment…

Any ideas?

Yes I see that also. I played a bit with tolerance and it seems not to be better. As I think that the transformation from curve to polygon is not perfect in this plugin, you could feed a polyline.

I think this plugin “Polygonize curve” comes from