General questions on machining (Adaptive clearing)

A multitude of options is both a blessing and a curse. If folks have good resources in this area please let me know.

My primary materials are wood with some limited plastic and brass/al. I use VCarve Pro and FreeCad.

If I get anything wrong please correct me.

Adaptive clearing:

  • A feature in FreeCad and I believe in Fusion 360
  • supposed to be up to 40% faster and provide better tool wear (uses the whole bit length not just the tip, it uses a ramp path to go full depth)

Do people really find it faster? What kind of step over is used? Does it leave a reasonable finish on the perimeter and bottoms, or is this a “hogging operation”

Hi Carl (or Lynn) - adaptive clearing ensures" constant radial engagement of the bit, reducing the stress/force on the bit while cutting. It does not use the whole bit length - it attempts to ensure maximum contact with the radius of the bit. Because of the more consistent engagement, you can generally cut faster and deeper. In that regard, it can be faster, though it produces a lot more non-engaged movements so that eats away at the efficiency from a time perspective. Using the same speeds and feeds, an adaptive cut will usually take longer than a normal pocket, but again, you shouldn’t use the same settings.

As for surface finish, it is generally OK, but I would recommend a finishing pass with a much lower stepover if you are looking for an excellent ‘off the machine’ finish.

Hope that helps!


Thanks Tom, and it is Carl.

I was a little fast and loose with the “whole bit length” phrase … you are correct that the engagement would be the pocket depth, not the bit cut length.

FreeCad does offer a “Finishing Profile” option similar to Vcarve Pros pocket … so I guess it is off to the machine to run tests. Unfortunately building first hand experience takes lots of machine time… but if folks are interested I will try to share.