3D contour wont follow selected chain

[a_youssryAQBN2]

3D contour sometimes bugs out and starts cutting edges I did not define for it to cut where as using a 2d contour with the same chain selected behaves as expected.

[a.laasW8M6T]

Hi

that's because unlike 2d contour, 3d contour doesn't follow chains, you define a boundary and it machines everything inside the boundary.

if you want similar behaviour to 2d contour but for 3d curves you should use the trace toolpath

[a_youssryAQBN2]

ok so if I want a to create a 3d contour for a tapered angle like the one here ( I edited the model from the previous images ). I choose boundary as pocket and selected the outer face. It seemed to work.

[a.laasW8M6T]

Hi

While that make work in this case, I think you may be misunderstanding how boundaries work for 3d toolpaths

If you can share that file we can demonstrate correctly how to select boundaries and some alternative methods of containing toolpaths, and alternative toolpaths to machine features like that

To share your file Goto File>Export>save as .f3d/.f3z

[a_youssryAQBN2]

it was a test model with just a tapered extrude with a hole inside it.