Better way to machine 3D fillet

[5X-machines]

Hey everyone

I've got a part with a fillet along a curved surface and been having trouble creating a clean toolpath to machine it.

Ideally I would like a semi-finish and finish pass. Blend has gotten me the closest results but if I try to turn on stock to leave, the toolpath gets scrambled and leaves much of it untouched.

I've also tried trace and pencil but neither give good results right out the gate and I feel there should be an easier way then to make a bunch of sketches to drive them.

Any suggestions?

[DarthBane55]

This will work, but still had to create a sketch.  A very simple one though, just a circle.  Picture below, and file attached.  Semi-finish and finish pass (project toolpath).

Note: I just did the toolpath, did not tweak anything like S&F or correct X-Y axis orientation, or anything else.

PS: I would think that pencil is made just for exactly this kind of stuff, but I have never been able to do anything of any value with it.  If someone can demonstrate with this sample how to make it work with pencil, that would be great.  If not, maybe someone can explain exactly what pencil mill would be ideal for... thanks!

 

[mattdlr89]

@DarthBane55 

I'd also like to know when/why to use pencil machining?

[seth.madore · Accepted solution]

Overthickness. This function isn't one that's self evident, and it's the key to the whole Pencil thing working:

 Shown above with a .005" overthickness value (found in the Passes tab), no other changes were made.

Imagine a machining world with Multi-Axis Pencil, wouldn't that be something!

[DarthBane55]

I'll be damned!  Thanks Seth!  I was able to make a clean toolpath after a bit of trials.  There was always a little loop happening in a few places, so I had to find the magic number under "tolerance" to avoid the loops, which was 0.0003".  Anything else, like 0.0001, 0.0002, 0.0004, etc, would produce some loops around the path.  At least it worked and this gave me a better understanding of that toolpath.

Yeah, would be great with 5-axis, but according to the roadmap...  it is coming...  we'll see...

Thanks again!