CNC Plasma undersized ID's

[madkins]

Our plasma table (Burny 1250 controller) consistently cuts inside diameters undersized, as if it doesn't account for the kerf properly. The outside dimensions are fine. I have been trying to come up with a rule of thumb like "increase the ID by 25% of the material thickness when using the 70A tip", to compensate but this seems a bit ridiculous...

Is this the nature of the beast? Should I scrutinize the Burny 1250 or our G-code generator (Turbonest)? I tend to think the Burny because even the pre-programmed shape library built into the Burny yields undersized ID's...

Any thoughts or comments are surely appreciated.
Thanks,
Mike

[jimcolt]

Have you spoken with the tech's at Burny? They are very helpful.
There also are some machine codes that affect this....I'm not sure of the number but I think they are called "kerf left" and "kerf right"....if one is deactivated it could cause this issue.

Jim Colt