Resonance calibration noise before each print

Bambu Lab P1 Series Troubleshooting
1

New to 3D print and got my P1S last weekend.

Everything goes well but there are two pulses of loud motor noise before each print which sounds like the loudest noise I can hear in a full calibration process.

It seems that M970.3/M974 in machine start g-code causes the noise:

;===== mech mode fast check============================
;G1 X128 Y128 Z10 F20000
;M400 P200
;M970.3 Q1 A7 B30 C80  H15 K0
;M974 Q1 S2 P0

;G1 X128 Y128 Z10 F20000
;M400 P200
;M970.3 Q0 A7 B30 C90 Q0 H15 K0
;M974 Q0 S2 P0

M975 S1
G1 F30000
G1 X230 Y15
G28 X ; re-home XY
;===== fmech mode fast check============================

Is it normal to hear such a loud noise for this “fast” check? Is it necessary to run the fast check for every new print?

Relevant topics:

2

It’s normal. The printer does a resonance sweep at the start of every print. Two different frequency bands, a second or two each time. If it detects that the resonant properties of the mechanics have changed, it will post a warning that you need to tighten belts and clean rods.

Yeah. It’s loud. :slight_smile:

If you get yourself a heavy stone/concrete tile and you put the printer on that, the additional mass will reduce how much the printer’s resonance sweep excites the surface it’s sitting on. That excitation causes some amplification of the noise. The added mass might also improve high speed printing performance depending on how “wobbly” the table/bench is.

3 Likes