Quick Guide to Cutter Compensation
CNC machines have three main types of compensation:
Control Radius G41
The first type of compensation is compensation that accounts for the size or diameter of the cutting tool. This is often referred to as simply cutter compensation.
Wear G41 plus value
Most shops that strictly use CAM software to generate toolpaths use "Wear" compensation, as there is more flexibility with smaller lead in or outs. If your 1/4" diameter tool measured .251" and your tool offset table had a 0.001" diameter you would only need a 0.0006" lead in or out to on or off your cutter comp.
Inverse Wear G42
This is identical to "Wear," except you enter the wear adjustment opposite of "Wear". Example: If you needed to make a boss .001" smaller you would change the diameter offset table incrementally +.001. This is drive by settings in the machine control and is less common that standard wear comp.
These compensation modes allow the machine to accommodate for things such as the location of a part in the machine or the size of a cutting tool.
Compensation allows the machine to adjust how it reads the CNC G-code so that the same program can be used in multiple ways.
Using compensation modes allows the CNC to run the same program and get the same results even if the factors we mentioned above (cutting tool, workpiece location) are changed between runs.
The machine will have no problem adjusting for a new cutter as long as we tell the machine the diameter and length of the new cutting tool.
The values that tell the machine how long the tool is or what its diameter is are called offsets.
There are multiple compensation codes and offset codes.
Luckily, the list isn’t long. Let’s go through them one by one.