You may want to print a cube of say 30 mm x-y-z and check the measurement. It should be pretty accurate. Make sure you have set the flow rate to 1 - do not use the LIDAR function a this time. You can also have a look here. The esteps, which are important to achieve dimensial accuracy as well should be (or are) set at correct value. This is what I haven taken from my X1 since a cube delivers almost prefect measurements. https://teachingtechyt.github.io/calibration.html#flow
I have found with small items and that style of caliper that changes in pressure on the adjustment wheel can cause significant changes in reading. Please try a larger item. I’ve made quite a few prints where exact dimensions matter, and the results have always been good.
Ok, that is pretty good, no ? the small deviations of .1 mm .2 mm are either mistakes when measuring or filament shrinkage . what is your flow rate now ? I would let go and accept this, especially when the wall shows 0.4 mm - I would call it shrinkage…
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.
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.