Chamfer bug using TRACE for 3D chamfers

[hatch789]

When entering a simple 3D chamfer toolpath using TRACE because it's on a 3D surface, the chamfer function appears to have a bug with radial tip offset. Using a 90 degree chamfer endmill Fusion is properly calculating the the axial chamfer tip offset but it's not moving in radially the same distance. With a 90 degree chamfer mill, adding a chamfer tip offset should result in the tip moving down just as much as it moves in. Right now it's ONLY moving down the distance specified in the chamfer tip offset. Chamfer width appears to be calculating properly and working correctly. But not the tip offset.

[chris]

There hasn't been any movement here from Fusion. I am experiencing this exact same issue.

[seth.madore]

Trace is extremely limited in how it works for 3D surfaces. Could either of you share a sample file that shows your issues?

[chris]

Certainly. I'm doing the Titans of CNC Building Blocks course and am on the TITAN-9M part. Here is the Fusion 360 sharable link to my design. https://a360.co/3LOrshN

The issue is in the last setup titled "Trace Chamfer 3D Edges". It works, but only if I set Chamfer Width/Tip Offset to 0. What I want to do is select the bottom edge of my chamfers so that the chamfer width comes from my model and not me manually setting it. Thus I want width=0. But what I also want is to not be cutting at the very tip of the chamfer tool. Typically would set to a number around .04 to .06 to vary it a little without risking the tool hitting something deeper. You can see that working correctly on the prior step titled "2D Contour Chamfer Inner Holes" where I set the tip offset to 0.05 in.

I've tried to manually trick the trace out by playing with Axial Offset and setting Chamfer Width, tried using Stock to Leave to move down and out .05. All those either lead to cancelling each other out and I'm still cutting at the tip, or I'm way overcutting the chamfer.

For reference, Titans of CNC course. I'm not doing the CAM the same way intentionally though, so I'm doing a few different approaches than the course at this point. Many ways to get the same result so mostly a style preference.

https://academy.titansofcnc.com/series/titan-9m

[seth.madore]

You need to set Sideways Compensation to Left and then you can define a Tip Offset of whatever you want:

There is a warning about the "flute isn't long enough", but that's rubbbish.

 

[chris]

That works and makes total sense, especially when comparing to the 2D Contour operation which does the same thing. Thanks for figuring that out, and letting me know I can ignore that flute warning.