Small Circle accurate?

[myprinter]

Doing some mechanic design. This is Not a software or design problem.

When printing small shaft or hole the diameter is not accurate. From about 4,5mm and up it is spot on!
Calibration is spot on with a 30x15 mm cube and layer height is spot on too.
Only small parts about <4,5mm round parts have problem with the accuracy. Parts are printed round!

Can it be slip or play in the moving parts on my printer, or maybe x-y stepper or what else?

[zemlin]

There are a lot of factors that come into play for dimensional accuracy. I have a system I developed for coming up with values for X&Y scale and horizonal offset that has worked well for me. Going real small on holes can still be a little tricky - like the tap drill for a 2mm thread is 1.6mm. I usually run a drill through the hole before tapping, even though it's pretty close.

I usually get +/- .02mm with this tool. viewtopic.php?f=9&t=6130&p=26646&hilit= ... oss#p26646