Perfect shaped circles needed - Please help

[organetic]

Hi fellows!

I have just completed my own diy cnc wood cutting table with 3x4meters.

The table itself is very robust, and I have used standard module 1 SR1-500 (http://www.qtcgears.com/KHK/index_Ra...les/khk144.htm) racks and 16 teeth pinions attached to Oriental Motors Vexta PK296-SG18 steppers.

I have tunned the motors and calibrated it in a way that there's no more than 1 milimeter error on it's full lenght.

What happens is that when I fire up Mach3 and try to make circles, they are pretty irregular, with some of them almost oval shaped.
Otherwise, when I cut rectangles or squares, everything is ok.

Could you please advise me on what to do to make perfet shaped circles?

Regards,
Org

[ger21]

Can you post a pic of your circles?