Size matters, so how to make the printer do as it's told?

Bambu Lab X1 Series Bambu Lab X1C
1

Today i printed an object that should fit an existing product.
Y=200 mm and X=223 mm
however after printing it did not fit, the X was one mm short, namely 222 mm

so now i’m wondering how this could have happened, i checked the file and even in the bambu slicer it states that the size is correct and i can live with a few tenth of mm, but this is too much off.

is there any way to calibrate the X1C so it is accurate or should i do maintenance, like adjusting the belts or something?

the printer has less than 100 hours of printing.

you might think, why i haven’t found out earlyer? well, most things i print should fit other printed elements, after checking it seems those parts are equally wrong in size, so they fit.
and when it’s small, like 40x40mm it’s only 0.2mm off in the X direction.

any help appreciated.

2

FDM prints shrink, large prints shrink more.

You can compensate using Process settings in Studio:
https://wiki.bambulab.com/en/software/bambu-studio/xy-hole-contour-compensation

Or use OrcaSlicer, which also lets you allow for shrinkage in the filament preset.

3

i do understand that the prints shrink, that’s why i gave the sizes in mm. in fact it is 1.37mm short on X and Y is 0.23 short after printing.

however, your answer is not the likely cause.
because i would assume shrinking happens equally in all directions, not more in X.

but since it could be a viable workaround for this flaw.
i will try to make compensation if nobody comes up with a better answer.

4

it does not work, since it just scales the print over both X and Y.

5

I’m afraid your expectations exceed the current state of the art. FDM printing simply does not produce the level of accuracy that it seems you want. I feel your pain. If you’re trying to reach that level of precision, you’ll want to do it in the original CAD model and perform test prints, then calibrate and repeat until you have the level of precision you desire.

To achieve precise dimensions in 3D printing, I design a test shape in CAD that mirrors the density and geometry of the target object. Density is crucial to account for shrinkage, and note that infill will significantly affect both density and shrinkage. Therefore, precise calibration depends on maintaining consistent infill and not changing it between prints. For instance, to ensure accuracy in the distance between two walls, I create a model specifically for that measurement. After printing, I measure the output and compare it to the CAD design, then adjust the CAD dimensions accordingly and repeat the process. While this method is tedious and must be done for each filament type, it’s the most effective approach I’ve found for achieving the level of precision you’re seeking. As you’ve noted, X-Y compensation is a blunt instrument.

One day they might introduce separate X and Y compensation but for now, that’s our only hammer and therefore every item in the world is just a nail. :wink: