Problem Slicing / Printing Accurate Inside Diameters

[morrisey0]

This one is a little weird, and it is throwing me for a loop. Let me just let the examples I have printed the last couple of days ask the question.

Basic 12mm pin / hex wheel adapter in varying heights. Cross section prints out 11.99-12.02mm, and heights come out within .1mm of design. My inner diameter is designed at 4.8mm, and it comes out ~4.45mm. I adjust the design out to 5mm, and they print ~4.6mm.

Then some very basic spacers I needed today. 12.5mm OD, 9.6mm ID. Again, OD and height come out just fine, but ID of parts is ~9.4mm.

They don't seem to be elephant-footing, and that would screw up the OD also. Everything seems to be just dandy except for IDs. Ideas?

Machine is a Bambu X1-Cardon. Filament basic PLA.

[Frankentruck]

What size nozzle are you using? Have you tried a smaller nozzle?

[silvertriple]

I generally do the inside diameters at +.1mm and if not perfect I use a drill bit at the rigth diameter, with my hand (and this is also valid for powder base printing process).
And generally, the smaller the diameter is, the more there is chance that drilling is required...

There is also a setting X-Y hole compensation in Bambu Studio that I suppose is designed for this, but I never used it.

[Dadio]

To do it properly then use the x y hole expansion in the slicer but this means calibrating I'd guess , it's usually simper to just adjust it in the middle as you have , it's just trial and error , from what I gather it's kind of a differential effect that causes it , it means the outside of the circle is more spread out but the inside is more compressed so it squishes inward .

[morrisey0]

So far, an X-Y hole adjustment is the fix. A little further explanation here: https://wiki.bambulab.com/en/software/bambu-studio/xy-hole-contour-compensation I dialed it in to about a +.15, and my two current parts are looking much better. I will keep a closer eye on it in the future to see if I need to change it with different materials or anything. Thanks for the help!