Calibration settings?

Bambu Lab H2 Series
1

I have found that the dimensions of STL going in, do not equate coming out. If I have a 4mm wall, it prints out at 3.■■ mm. Slots are undersized while the corresponding part is oversized making it difficult to assemble and requiring sanding. Even using the Vision Encoder doesn’t seem to matter. laying flat, circles are circles and squares are square, but the actual dimensions are off.

With 2 H2D, I can run the same part, using same brand filament, that is calibrated, and come up with two different sized parts. For example I have this part that is 2.5mm thick, its a T shape and prints the wide part on the plate and the skinny part on top, like an upside down T, 20mm long, measures 19.91. the T part is 5mm wide, comes out at 5.06 mm, and the stem of the T is 2.5mm wide but comes out at 2.56 mm. The slot it goes into is 2.6mm wide, but measures at 2.38 mm.

How do I adjust for this?

2

When calibrating filament, I do the following:

  1. Perform the Pressure Advance (K value) calibration in Bambu Studio. This is the first step of the manual calibration.
  2. I use this model to determine the Flow Ratio to make parts fit together nicely.

Make sure to download the spreadsheet and follow the directions in the spreadsheet for slicer settings. I usually print 5 parts each time to get a statistical sample.

2 Likes
3

Wall widths not matching spec - would try troubleshooting flow ratio specifically

Also make sure you are measuring in a way that doesn’t touch the bottom surface’s elephant foot, that will ruin a lot of fine measurements.

4

That I discovered a while back so only measure on the flats, and if I can, put the bulge in the caliper notch.

Running the full calibration suite, but since I use a few different brands, need to run it on each brand, just to be sure. Since I use a lot of Kingroon PLA and Sunlu PETG, those will be the first.

5

This is fantastic! Thanks for sharing this? I didn’t know this even existed.

6

What the heck is the VFA calibration for? Looks like angles.

7

Vertical Fine Artifacts :wink:

means vertical waves on the outer walls…

8

Ah, in that case, mine is freeking perfect! I was wondering because it looks nice and smooth all over, except where I accidently turned off the power to the subpanel, oops.

9

Well, I think I got it. I ran Temperature first, then a manual Flow Rate, then the PA and after that point, just an adjustment to temperature it was printing perfect. Those test pieces fit perfect printing one off each machine. I actually had to boost the numbers on the PA to get a fault, which turned out to be an extractor fault. Boosted Max Volumetric to 29, which is actually a bit below where the print failed at 34. The VFA turned out beautiful too. Now doing it with some PLA Clear Transparent to see if it will print properly. Have 3.5mm holes that prints at 3.2mm.