[BUG] FT_MOTION produces strange sound

[vovodroid]

Did you test the latest bugfix-2.1.x code?

Yes, and the problem still exists.

Bug Description

There is different, strange motion sound with FTM enabled (without IS). See also #26848 (comment)

Default:

default.mp4

FTM:

ftm.mp4

Spectrogram:

BTT 3.0, TMC 2209

I'll try to take oscillograms later.

Bug Timeline

No response

Expected behavior

No response

Actual behavior

No response

Steps to Reproduce

No response

Version of Marlin Firmware

bugfix-2.1.x 2024-08-07

Printer model

No response

Electronics

No response

LCD/Controller

No response

Other add-ons

No response

Bed Leveling

None

Your Slicer

None

Host Software

None

Don't forget to include

• A ZIP file containing your Configuration.h and Configuration_adv.h.

Additional information & file uploads

Marlin.zip

[thisiskeithb]

I'll mark this as confirmed since I was the one who reported the issue in the referenced PR.

cc: @ulendoalex & @narno2202

[narno2202]

On my side no strange sounds (MKS Monster8 V1.0, TMC2226) when FT_MOTION is enabled and the printer idle. When axes are moving as the timings are different from standard motion, the produced sound is also different : normal behavior.

[vovodroid]

Can we be sure that it doesn't damage drivers?

[thisiskeithb]

When axes are moving as the timings are different from standard motion, the produced sound is also different : normal behavior.

I also run 2209s, 2226s, & 5160s on various machines and the high-pitched whine & crunchy sounds cannot possibly be considered normal. They sound terrible with FT_MOTION.

Motors sound completely fine with standard motion / Input Shaping.

[vovodroid]

Could you record your printer? 

[narno2202]

I'm currently transcoding the recordings

[narno2202]

Here are the two files : 100mm X motion via Octoprint.
First without FTM, seconf with FTM.

17_28.mp4

17_29.mp4

[vovodroid]

@narno2202 as for me your FTM sounds is the same as without, I can't distinguish. But besides higher pitch my has strange 350 Hz pulses:

Is is supposed to be during movement without IS?

[vovodroid]

@thisiskeithb could you upload your sound recordings?

[thisiskeithb]

could you upload your sound recordings?

My phone doesn’t pick up the differences very well and I don’t have any other kind of recording equipment.

[narno2202]

Since the beginning the pitch is slightly higher. @ulendoalex says that is the normal sound as timings are different (but they respect stepper specs).