I suggest doing a flow calibration - the OrcaSlicer fork has test patterns for this. The other thing that comes to mind is that the filament you’re using may be underextruding at speed; you could run a max volumetric test too.
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I’ll throw this in here. I had the same problem and I had done the “loosen the screws and move the carriage” routine here:
So I was pretty annoyed that I I still had a problem.
I was reading another post that said to do it again but move it FULLY to the stops and do it at least 12 or more times, so I tried that and it was much improved.
After I also did the full set of Calibrations several people here mentioned in OrcaSlicer I found it to be pretty darn good. My “parts don’t mate” problem is gone.
So give another try, I’m sure Support will tell you the same thing before they’ll discuss other options. BTW - They’re running pretty slow right now as they get new support people trained, so be patient.
One other thing - don’t run the carriage back and forth too fast, if you really push it fast the servos turn into generators and feed power backwards into the motherboard. You can tell you’re going too fast if you see the Bambu Labs Logo LEDs on the carriage start to light up, if it does, slow down. 
Good luck.
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Someone speaking from experience there? 
Who me? 
Fortunately I’ve been an Electronic Tech since I was a kid and ran into this with my 1st 3D printer, it had a power LED on the main board.
I saw it and went 
and started laughing when I realized how many people were going to have problems when they got impatient, so fortunately, no.
But I’ve made up for it many other ways, trust me.
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Hello. I’m back.
I checked the belt and I did few tests.
I think that the real pain for this printer are circles and holes. I printed a square and a circle togheter.
The square are almost perfect.
The circle is 0.2 smaller.
Any idea? If I change che xy compensation on the bambù studio will it change the general behavior or only for the circles?
Thanks
Well that’s looking loads better! 
There was a pretty long discussion of holes that if you have the time you might read, lots of good ideas and discussions in there including the XY Compensation. Here:
https://forum.bambulab.com/t/why-ovals-and-not-circles
BTW - In the top picture of the circle (inside diameter) it looks like the calipers are not square in the hole, it may be perspective…
Measuring inside diameter can be tricky, be sure to measure at multiple points around the circle. Best practice is to mark the X and Y directions before pulling from the print plate.
But you’re definitely making progress. 3D printing teaches life skills - patience amongst others… LOL
Well done!
what is this for a answer??
of course you can calibrate it, like every other 3d printer as well…
and you should.
there are so many examples and ways to calibrate it.
after the autom. calibrations you have to check and do the belt calibration (frequence) and then you can do additional flow calibration for best results.
The answer is correct - you cannot do traditional X and Y steps calibration on the Bambu printers. Yes, you can calibrate flow and Pressure Advance. The frequency calibration is an internal thing. Please read the original question before responding.
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Seconding the comment from @ThanksForAsking above, calipers are very iffy for measuring inside diameters, it’s very easy to measure undersize on a hole that’s actually the correct ID. In particular, when the part isn’t perfectly square to the jaws (as it appear to be in the image above), the jaws will be kept from “bottoming out” in the curve because they’re actually contacting the walls of the bore slightly away from dead center. The part actually needs to be perfectly square to the jaws in both axes or you’ll get the same effect. I’d bet that the 0.2mm you’re short there would be corrected by reorienting the part.
The 0.21 undersize on the cylinder is another matter. I don’t know if it could be an issue here, as I haven’t printed anything that I needed really close tolerances on yet, but I do know that so-called “input shaping” to avoid resonances at high speeds can interfere with part accuracy. Just to eliminate that, I’d suggest running the cylinder at a very slow speed, and see if the dimension changes any. (I dunno how slow to say, but to completely eliminate it as a possibility, maybe go all the way down to 30mm/s or so.) Let us know if that changes anything. If everything is properly tuned in their mechanical system it shouldn’t matter, but it’s the main thing I can think of, given that straight-edged parts seem to be dead on.
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Hey there 
I’m having very similar issues as the OP and am hoping for some kind of X-Y calibration feature.
I have built, owned & operated plenty of printers and I have always managed to get precise and repeatable prints within 0,05mm out of them. I know that caliper measurements of the inside of holes (especially small ones) are difficult to take, and what factors lead to errors both during printing as well as during measuring those, but I’m having around 0.5% dimenional errors even on the outside of square test bodies.
20mm → 19.92mm
40mm → 39,82mm
100mm–> 99,35mm
200mm → 199,1mm
I have reached the point where I have to use the “Scale [S]” feature of Bambu Studio with a factor of 100.5% to get dimensionally accurate prints.
Also worth mentioning:
- The error scales almost linearly with the size of the parts
- It can be observed even when measuring the movement of the printhead directly.
- It is perfectly repeatable. When I do 10 test prints of a 100mm part the standart deviation is 0,04mm
This printer is such a reliable machine and so well manucatured, that I find it a pity having to manually scale XY while a fix could be done with 5 lines of code allowing users to set two parameters.
Hoping for this feature to come
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This the same exact number I’ve obtained when doing my tests. I hope they had X-Y calibration settings in the slicer instead of the Scale feature.
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So I have to apply 100.5% on x and y … and how about the z? How do you set it?
Vertical holes are almost ellipsis.
. Thanks
I found no cure for Z. When using the scale feature, it will either add a layer (typically 0.2mm for me) or nothing and 0.2mm is too much for small objects. For example, my 20mm object goes from 19.92 to 20.12. I guess Z scaling could be used on tall objects if the print is too short by at least one layer height.
Circles not round is another issue. There are threads about it.
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For really coarse adjustments you could still use the “Scale [S]” feature on Z, but you will always end up with whatever the incremental nature of the layers will give you. Smaller layer heights will give you a better approximation. See if that helps for top surfaces.
The slight un-roundness of holes on the sides of bodies is IMHO within the usual tolerance of what I’m used to seeing in FDM. If I ever observed it, I attributed it to overhang-drooping in the upper section of the circle. Smaller layer heights may improve this as well.
Also, whenever I have holes that need a very tight fit, I design the part in a way that allows me to drill-out the holes to the desired dimension.
I did a test.
Z was supposed to be 50. It is 49.85
Pressure advance calibrated at 0.02
Now i got this.
I used adaptive layer. 0.5 adaptive and 5 radius.
What’s wrong now?
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Looks like a poorly / none calibrated material. I suggest first calibrating the filament, to ensure a reliable base variable.
In addition, the messurement is still in tolerance for additive fdm manufacturing.
I did pressure adv test and temp test.
Am I missing some ohter test?
Thanks
Flow rate is an important test for print quality,
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exactly the same number i get! so its a common issue