SHAPER_CALIBRATE versus TEST_RESONANCES

General Discussion
1

Basic Information:

Printer Model: Ender 3
MCU / Printerboard: BTT SKR Mini E3 V1.2

Describe your issue:

I installed a single ADXL345 to the X and then Y axis on my Ender3 and ran the TEST_RESONANCE on each. After complete, I have both files that show the resonance for each axis.

shaper_calibrate_x
shaper_calibrate_x800×600 102 KB

I forgot to save the csv files when I shut down last night so those are gone. Based on what I read in the guide (Measuring Resonances - Klipper documentation) I just need to add max_accel and max_smoothing to my config. I already had a more restrictive value for max_accel but I added max_smoothing that split the difference (0.12 and 0.14 for the 2 tests).

[printer]
kinematics: cartesian
max_velocity: 300
max_accel: 3000
max_z_velocity: 5
max_z_accel: 100

[resonance_tester]
accel_chip: adxl345
probe_points:
    100, 100, 20  # an example
max_smoothing: 0.13

Now I’m wondering if it would be beneficial to run the auto calibrate instead? Just curious if rerunning will get me anything more than what I already applied. I don’t want to shake the machine for no reason. Also, I’m going to be adding z-braces when my dual z-axis kit comes later this week so I’ll have to redo this at that point anyway.

2

shaper_calibrate_y
shaper_calibrate_y800×600 110 KB

3

FWIW, I decided to run the SHAPER_CALIBRATE on each axis and SAVE_CONFIG. It looked like there was probably a way to manually do this but it wasn’t worth the effort to figure out the code. If someone knows an answer it would likely help others but otherwise I guess this can be closed.

4

Please carefully re-read the documentation. Both values are not configuration settings

  • max_accel is a recommendation not to exceed the given acceleration or excessive smoothing will kick in. It is also NOT a recommendation to use this accel for your printer.
  • max_smoothing is an indication of the the amount of smoothing to be expected given the chosen shaper and frequency profile. It should be considered as a qualitative statement for comparing the different shapers.

Your best bet is to use SHAPER_CALIBRATE as you already did

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