So I've been blaming a bad bearing for this noise.

So I’ve been blaming a bad bearing for this noise. I figured it had to be it because when the bad bearing seized it broke my Y carriage bearing clamp. Yesterday I printed a new carriage in limp mode and tore the thing apart and threw it back together. For the first 5 mins it sounded nice (i even have video to prove it) I was feeling accomplished so I started a print. The noise is back almost immediately. All I can figure is it seems to come from the bed.

This noise carries , the lady next door doesn’t like it when I print at night and clearly if Y worked like X does I could.

This is what I am trying to achieve during prints.

This Highlights what the ‘problem’ is . About 8 seconds you see X go into action. It makes a nice whip whip whip whip noise. At 12 seconds the joy killing noise kicks in . It is more of a ZZZZZZZZZT .

Ive tried to track down and nuts in the beams that are not secure.
Ive replaced ALL the bearings twice.
Ive replaced the idler bearing.

Initial reports seem to indicate Ive got mine running considerably quieter than an identical printer. I think this is the best i can do ?

well i’m doing a repstrap (and a big one at 42 cubic inches ) and most of the time it gets noisy if i either dont calibrate the current for a given stepper properly or if i have crap on my rods (smooth and threads)

I think I just found it. The tensioner uses screws to force the idler out. Where those screws contact the openbeam was all torn up (scratches and things) I stuck some rubber feet on the openbeam where it contacts, and the rattle is gone. It still hums but considerably quieter than an identical printer. so i think i got it.