For my first TPU print I wanted to do my flow rate calibration.
My TPU is from creality and I started with a flow of 1.
I got some unsuccessful try with with pass 1 with orca from -20 to +20 with nothing comming of the noozle after a few minutes. I stoped the print.
Then I tried only with YOLO from -0.02 to 0.02. (who gives 0,98, 1 and 1,2)
This worked fine. as y can see on the picture
But after this I wanted to do a complete calibration and then the 1 flow did not print correctly and the next 0.01 (who gives 1.1) did print as if the noozle was clogged.
So sometimes it prints and sometimes not… whith same settings.
Filament profile is Generic TPU.
Door and upper glass are opened.
My filament was dried 8 h this night.
What should I change to my settings to avoid this ?
I usually start calibration with a temperature tower. The YOLO flow test has not worked well for me. Twice I have needed adjustments that were beyond the tested range, so I had to run the 2-pass test anyway.
I do not see much difference between the -0.2 and 0.2 samples in your pictures and I would expect the correct value to have a much smoother surface.
The standard two-pass flow test can be sped up. I have never needed the ±20 samples, so in the object menu I uncheck flowrate_20 and flowrate_m20 before slicing - that saves 15 minutes with TPU. Then I watch the print and use Handy to skip the samples that are beginning to show signs of being incorrect.
At first pass I tried with +0.2 0 -0.2 with initial 1 flow
With thi,s +0.2 gives over extrusion and 0 was a little better than +0.1
At second pass from 0 to -0.05, I choose -0.1 but it was very similar to 0.
The surface is not so smooth
For the next try I think I will keep retraction off.
But I will try to increase volumetric speed to Bambu default value 3.3 and speed to 30 mm/s again.
Do you mean you use your handy to zoom on the test ?
Or something else ?
I tried the calibration step by step but other calibration as flow rate failed with the same problem : after a few seconds (or minutes) nothing comes out of the noozle. And it continue to print and either nothing comes from the noozle or some filament comes and print in a vacuum.
The only thing who works well is the flow rate calibration.
I tried from 0.9 to 0.95 again and got 0.91 (0.95 failed).
But the temperature calibration and tower pressure advance calibration stops with a stuffy noozle.
For the print settings I use 0.20mm Standard @BBL X1C
And for the filament picture is in attachment.
I dried my filament 12h again this night to be sure.
