Buzzing after all metal extruder upgrade

[PcS]

Ever since the upgrade I have had this annoying buzzing when printing...extruding. Have switched extruder motors. Tried with and without fans.Prints turn out fine and I have not noticed any adverse issues with the printer otherwise. Anybody else experience this ? I have a video link here https://goo.gl/photos/puAPthRHMC1dBBym8. I do have 3volts a.c. between the filament drive bearing and the z slide rods when printing with my ohm meter. Have not figured out why but I think it is the culprit.

[willnewton]

Wow, mine was just doing this last night and I was like, "What is that?"

I wondering if there was a loose bolt or nut. I have had my metal mount for a few weeks, but last night was the first time I heard it. I heard it while working in a room next to the printer, it wasn't loud, but enough that I went over to check. There was nothing obvious and it was bedtime, so I let it keep printing.

I did change my speed for that print and wondered if I was getting some resonance. It was set to 70mm/sec, it was printing layer one at 60% speed and working on infill at 80% of that speed.

The first layer was going down well and was rather large, so I went to bed. I haven't even walked out to the garage and seen if the print worked out this morning.

I'll go check it out and put my meter on it to see if I read any voltage like you did.

After coffee.

[PcS]

Thanks !!! At least I am not alone. Print speed does not seems to matter for me. I am printing at 30mms right now and it never goes away. Heated bed at 80C and hotend at 262C. I may try with bed off next print and see if that has anything to do with it. Although this is a long print so it will be awhile. I`m on my second strong cup of coffee. !!!

[willnewton]

OK, the print came out fine.
I started a reprint and got the same noise.
I checked for voltage to the chassis and there is not any.
I checked all the bolts and they seem OK.
**Definitely coming from the extruder gear/filament drive area. I checked and the bolts are all tight.
Removed the entire fan assembly and still had noise.
Tested with just a basic extrude, no XYZ moves, still makes a noise.
Removed filament, repeat above, still noisey.
Removed filament drive housing, repeat basic extrude.

•NO NOISE!•

Reinstalled filament drive, test extrude, no noise.
Reload filament, test extrude, no noise.
Reinstall fans, test extrude, no noise.
Restart same print, no noise.

So, my theory is that possibly the balls or races in the filament drive idler bearing are just slightly able to vibrate under the right conditions. Removing the filament drive and reinstalling it perhaps changed some of the conditions, shifting the resonant frequency to one that did not vibrate while extruding.

Don't know if this will solve my problem or yours, but it worked for me this morning. I'll update if it reverts back to making noise.

[PcS]

I have a spare I can swap in after the print finishes. Thanks for the help hopefully it fixes it for me as well.

[willnewton]

I don't know. I need to run a few more prints and hang around while they are going to be sure. It could have just stopped temporarily at the same time I removed and reattached the filament drive and will re-emerge in a few days or prints.

Correlation does not imply causation!

[PcS]

Swapped filament drives out from one printed in colofabb ngen to one printed in esun petg. Almost gone but still there. Changed from printing colorfabb ngen to esun petg and so far no trace of noise. Will monitor this 17hr print and see if it comes back. Seems as though for me choice of filament may be a factor as well.