Accuracy cutting cylindrical parts

Hi everyone, I finally set up my new Onefinity and started using the free version of Carbide Create.
I entered a R=1.145 (for DIA=2.29) for a circle. I used the contour with a .25 UPCUT bit. I told it to cut on the outside.
The resulting machined cylinder came out to be 2.20. .09" smaller than I anticipated.

  1. Is there a way to calibrate the software (Carbite Create?)
  2. Is there some adjustment in the Onefinity firmware set-up?
  3. Any other suggestions before I start in creasing the modeled radius till I get what I need?
    I really would like to get the output as close to the modeled dimension as I can.

Hi George,
Im not familiar with Carbide Create but that seems to be off quite a bit. In other softwares you can use cutter comp or you can “leave stock” to get what you want. Im sure the software has a way of doing that. By doing this you can fudge the diameter of the cutter to dial in a cut. If you tell the machine your cutter is smaller then your part will be bigger and vice versa. Another thought is if you are taking this in one pass you may want to try an offset pass and then a finish pass to sneak up on your diameter. This way the cutter is under low load for the finish cut and wont flex and stay on target. Hope this helps.

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Hi George - it is unlikely to be an issue with the CAD/CAM software itself. Maybe post processing, but accuracy issues like this are usually due to the machine itself or the control software. I would ensure you machine is properly calibrated but testing it moves the correct distance when commanded. Do this over various distances as any error in the steppers is usually more pronounced the further the machine travels. I made a post on how to correct the error if you have any. Hope this helps.

-Tom

Thank you Henry I will check it out.

Thank you Guru! I will check your other post out.