Hello,

Newbie here... (25+ years windows programming, 0 years CNC milling...)

I am milling an 0.025 circle using an 0.020 bit (haven't bought the bit yet) ... is there a command that accounts for the 0.020 size of the bit when milling so that the hole is truely 0.025 (and not 0.025 + the radius of the bit)?

I'd like to calculate my points as if the bit was 0.0, then enter a command for the bit size/offset and have everything work (i.e. let the controller figure it out).

Is there such a thing? Is this "interpolatiing"? 

Thanks!
-charlie

Cutter Compensation, G41 (left) and G42 (right). It's not quite as simple as adding the G41, you'll need to addd a lead in move where the compensation is applied, and then use G40 to turn off the compensation. Can you post the code for your circle without the compensation?

Thank you for your reply.

My VB.NET program is generating the center points and the ARC/CIRCLE commands... I'll just subtract the bit radius (writting custom app that generates GCode). Looks like it will be easier (and possibly more accurate) that way.

not sure now accurate (places to the right of the decimal) the computed compensation is good for. I'll be using a DECIMAL data type in VB.NET that is suppose to be good to 29 places total (10 to the right of the decimal)... In comparison, a DOUBLE data type is only good for 4 places to the right...

-charlie