How does Bobcad V29 Simulation Handle Cutter Compensation

Hi All,

I am trying to figure out how to do cutter comp and get the expected final results.

If I use "system" (Bobcam" doing the cutter comp) I always get what I want the final
part to look like after it's machined (in the simulation module).

If I use "machine compensation" (my machine does the comp via G42/G42) I don't always
get the simulated part to look like the final machined part. I use leads for G41/G42.
Using G41/G42 it, sometimes, looks like the simulation switches between compensation
and no compensation.

It will produce leads that simulation cuts outside of the pocket profile, even though
the lead paths are shown inside the pocket profile, outside of the simulation module.

I am missing something here.

The simulation module should always show you the final machined part, no matter which
method you use to do cutter compensation - otherwise what good is it?

Thank you for any help you can provide,

Paul Hoffman

Hello Paul,

A little late to respond, but....

This is how it works.

1) System Comp

System comp is when BobCAD will look at your tool size and offset for half it's diameter.

2) Machine Comp

Using machine comp, if you use a arc line lead in out, BobCAD will post a G41 or G42.



Using these two setting you can offset for your cutter in the following ways.

1) Turn off system comp and machine comp

BobCAD will cut on the center of your geometry. In other words no offset for the cutter takes place.


2) Turn system comp off and machine comp on.

BobCAD will cut on the center line of your geometry (no offset ) and G41 or G42 will be posted.


3) Turn system comp on and machine comp off.

BobCAD will offset for half your cutter and not post a G41 or G42.



4) Turn system comp on and machine comp off.

BobCAD will offset for half your cutter and post G41 and G42




You also might find this video on 2D Milling to be helpful.