why is 2D adaptive undercutting part?

[raiderH7M47]

When I use 2D Adaptive Clearing It always violates the model/part when I post code to mill and undercuts the part. When I use 2D contour my parts come out beautifully. What is my problem? I have stock to leave set at .020" Axial and Radial.

[a.laasW8M6T]

What is the machine and controller you are running the code on?

It sounds like a machine problem(Well maybe more of a machine limitation)

you aren't feeding very fast(But "Fast" is very machine dependent)

[raiderH7M47]

PM-25MV conversion with a Gecko G540 running UCCNC. Is it a speed thing? I can run 2D contour much faster with wonderful results. Do I need to leave like .100" on "Stock to Leave"? Adaptive should work with any configuration with the right parameters correct? I sure would like to use this feature.

[a.laasW8M6T · Accepted solution]

So, what you are seeing is a combination of Machine/Stepper/Controller settings that is causing the tool to overcut.

This is common in Older and lower quality machines running semi closed loop or in your case open loop? control of the motion.

You could probably make some improvement in the steeper tuning/UCCNC tuning, but I dont know anything about steppers, im more familiar with industrial servos.

One thing that may help is turning smoothing on in the adaptive toolpath.

With smoothing off you can see there are a lot of points, and every point is a line of code to process:

The code is 240kb in size

If we turn smoothing on:

Then the code is like half the size

And it should run much better on the machine, whether this fixes the undercutting problem I cannot say.

[raiderH7M47]

I just ran the test with .040" stock to leave and I was able to finish with enough stock to cleanup for good dimensions. I'll try the smoothing active with .020" in stock to leave and see what happens.

[raiderH7M47]

That was It! Smoothing, makes sense. trying to crunch all those data points made it to herky jerky. Thanks for your help!

[a.laasW8M6T]

Excellent, thats good to hear!

I suggest you set the smoothing on as default, in adaptives and 3d toolpaths, you can do this by right clicking on the toolpath and going to Compare and edit.

then search for smoothing, right click and set as user default

[raiderH7M47]

Awesome! Thanks for your help.