Hi my name is Ivan and I tried for first time a small Gcode, it is a  small gear I have done it with a pen on a paper but instead a round gear the result was a oval gear.
I would like to know why.

regards
     
Ivan

Could be a few things, but it's hard to say without a picture. Make sure your steps/unit are set correctly for both axis. It sounds like one axis may be set incorrectly. But a picture would help if it's something else causing it.