Cylinders are small but Cubes are accurate

I’m new to Bambu and don’t know what to expect in terms of dimensional accuracy. After printing several square/rectangular parts, I calculated my shrinkage value to be 99.4% for Polymaker ABS, red color. The ABS was dried before testing and has been sitting in the AMS2 at 7% humidity.

The round section of my part is consistently too small but the square portion is dimensionally correct. How do I make the round section bigger without affecting the square section?

I’ve tried:

  • Changing the shrink factor (makes the square too big)
  • Auto circle contour hole compensation (not much difference)
  • X-Y contour compensation (makes the square too big)
  • Slower print speed (made problem worse)
  • Bigger in CAD model (best solution but harder to manage)


I see other folks mentioning the same thing at:
https://www.reddit.com/r/BambuLab/comments/19clhfh/dimensional_accuracy_off_in_circles_not_squares/

https://github.com/bambulab/BambuStudio/issues/3972

https://www.reddit.com/r/BambuLab/comments/15kw4oc/bambulab_p1p_dimensional_accuracy_issue/

I believe contour compensation is what you’re looking for

https://wiki.bambulab.com/en/software/bambu-studio/xy-hole-contour-compensation

Thanks, but as I mentioned, I already tried that and listed the results in my table.

Oh you’re right, I completely glossed over that, my apologies