Mach 3 changing cut size

[Jb_engineering]

I made a design on inkscape to be a 600mm x 600mm circle, which was fine. Then imported it into sheetcam to create the gcode/ tap file. Which again was fine. However when i cut it uaing mach 3 it changed the size to 560mm for some reason. Any idea why this has happened?
Thanks.

[acourtjester]

If the steps per calibration is off (for both X and Y) that will cause a change in size. This would only happen if you made a change to the value, not by itself. In SheetCam you can see the size of the circle as a check while doing the plan. This is displayed on the bottom of the screen, move the curser to outside of the circle top and bottom.

[djreiswig]

Sheetcam also has a measure tool. Right click over a part of the drawing.

[Jb_engineering]

In sheetcam, it was the correct size. Just when its loaded into mach 3 it changes for some reason. Its only on circles though that it happens.

[acourtjester]

That comes back to the "steps per calibration" but that would also effect the other shape cuts.
When you are cutting a circle have you looked at the DRO for X and Y to see if it says the correct value

[Jb_engineering]

Not yet, i thought i would see what you guys may think. Its just strange that its only doing it on the circle. Only thing i can think of is that it could be down to the file name. As i cut it before at 400mm, with the name "boston". But this time i changed the size on inkscape and named it "boston600". And thats when ive had the problem in mach 3.