Cutter Compensation: when and how to use it

In this video, @GCodeTutor explains the basics of cutter compensation and how to program your CNC machine correctly using G-codes G41 or G42.

Why do we need cutter compensation? If didn't use cutter compensation and we programmed our tool paths to be the same size as our part, we would end up with a part undersized by the radius of our cutter. This is because we program to the center line of our cutter, so if we are programming our dimensions on our part, the centerline or the tool would follow that path and not the cutting edge.
So that means we either have to program our part a little bit bigger to compensate to the radius of our cutter or we can use cutter compensation.
When we use cutter compensation, the machine automatically compensate to the radius of our tool so that we are cutting to the size of the part.

For cutter compensation to work, the machine needs to know the diameter of our tool. So if we are using a 1/2" diameter tool, we would offset it by 1/4".
G41 and G42 are the two codes tha we need to include in the program in order for the machine to calculate the cutter compensation.
G41 is typically used when the cutter is on the left side of the material and it's commonly used in climb milling applications.
G42 is typically used when the cutter is on the right side of the material and it's common to use it for turning applications.

Cutter compensation can be applied in 3 different ways, depending on the machine controls.
The first way is by communicating to the machine the radius of the tool using the P command followed by the radius of the tool like in the following example:
G42 P5.0;

The second way, less common, uses an X value after the cutter comp G-code:
G42 X5.0;

And finally, the most common way is to just state G41 or G42 to let the machine know we wish to apply cutter compensation and let the machine take the geometry from the tool table and apply it.

Stay tuned for more machining videos!

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#Cuttercompensation #Gcode #CNCmachining

[Fikri_A]

Pretty helpful video for beginner like me

[TheMoneyman]

I am a CNC machinist, and I am still learning. In the shop I currently work at, we use wear to apply cutter comp. This is how I was taught, and I have never heard of using G-codes to apply cutter compensation. Is there any benefit to using G-codes over wear? And also, if I understand correctly, is cutter comp ultimately backing the tool off say (.0005) around an entire part being machined, such as the entire outer dimension? Any feedback would be greatly appreciated, thank you.

[hardcoreironman]

0:09 Nice torque test channel intro music.

[macca_]

We set the diameter of the tool in our CAM software and the g-code is programmed running on centerline but the coordinates are allready offset in the code. Eg: if the cutter is 10mm diam and it is milling on the edge of the workspace, the g-code coordinates will we -5mm. It reads the diam in the CAM software.
However there is an option to use g41/g42 in the settings in which case it will read the diam on the control? What is the advantge and disadvantage of either way?

[protocolpalpatine]

I can't get cutter comp to work at all using g42 p1.0. Or just g42 by themselves haas vf2

[trevornorth]

If you turn off cutter compensation while doing a linear move, does it change where the machine positions the tool, i.e.
will G1 G40 X1. cut the linear movement x1 while being offset still, or does it turn off cutter comp and then cut the 1 in the x direction?

[hikolanikola]

all fun and games untill machine starts trowing "367 cutter compensation interferance G01 cannot be done with tool size"

[manofallmasterofnone]

If I get a program that does not use cutter cutter comp, can I input the code for cutter compensation?