Outlining cuts off protruding ends of curved part

I’m working on reproducing a piece of wood corner trim. The piece looks like this:

Contouring in just the long direction looks like it will work nicely, but outlining is misbehaving. You can see that the tips of the part are lopped off during outlining:

(I’ve gotten used to “submitting bugs” here on the forum. If you’d prefer that I use the github issue tracker, just say the word. It doesn’t look very current, however.)


It’s easier to keep track of bugs / requests if it’s through the issues tracker, even if that hasn’t been popular of late. You can attach relevant files like the .km file I’m about to ask you for :wink: Or just drop it to me in Discord. This is a bit of an interesting case. I know what’s probably going on.

Well, I’m always happy to keep you interested. I’ll open an issue for the next one. Today I’ll just email you the .km file.

I could make a long-ish video about the complexities of process this shape given the current algorithmic approach. However, I think I will put that energy into the new code base that will take a different approach and handle these situations better. This is a very useful test case, though. So thanks for that.

@pgf do you get better result if, in the CAD model, you fill in the undercut by projecting the “shadow” of the part straight down?

Assuming that works: imo it would be fair for Stewart to declare undefined results for undercuts in CAM <= 2.4.

New issues in github, eh? Noted.

this undercut is an especially hard case right now because it’s along an edge curved in Z. had the edge been co-linear along Z, it would have been detected. there is a more reliable, but more computationally expensive, way to handle this which I plan to implement in 2.5.

I think that if I make the part wider, and perhaps play with the step down value for the cutter, that I might be able to make the ends that get snipped off be outside the bounds necessary for my part. I already have to do the cutting of the underside myself – it might actually be useful to have “extra” curved surface when I go to trim it (manually) to the right size. (I.e., right now the curve sweeps out 90 degrees. 100 might be perfect, then I’ll cut it to 90.) Sounds good, anyway!