Accuracy of the print

Hi, today i tried printing a mount for a dial gauge to place the bed as straight as possible. after printing it, not one measurement i took was like on mij drawing. How can i calibrate so that if i like want to print an 8mm diameter washer that i have that diameter and not 7.58 in my case?

[quote=“Jan Lauwers”]How can i calibrate so that if i like want to print an 8mm diameter washer that i have that diameter and not 7.58 in my case?[/quote]It’s a known slicer issue : inner circles are always too small. Only way to is to oversize the holes at design time.