Hello,
I’ve got a problem with custom set metric routerbits . I’ve tried to cut a circle with 60mm (cutting outside was sat) with a 1mm bit. but it came out with around 58-59 mm . In several try’s it was missing from 1-2mm … Did someone else got these issues?
Regards Jochen
Is your machine calibrated?
Do a 200mm jog = 200mm distance travelled?
Do you make the design in Easel or other software?
The design is made in easel… no im new the hobby I did no calibration… 
how can I do this?
Take a fine point bit and a ruler, lay the ruler down along the axis to be tested.
Move the bit to ruler 0 point, then command a jog command of some length, say 200mm and measure the actual travel.
If there is a discrepancy between commanded and measured distance some fine calibration will be needed. Until this is established there is no point in chasing the “missing 1-2mm” elsewhere 
Ok thank you!