Strange rattling noise  

RE:

Posted by: @jamie-porro

IMG_0811

Hi everyone.

 

Firstly, thank you for helping to trouble shoot this with me.

So I am printing a tiara for my daughter and have had mixed success with it with a collision in one instance causing one layer to shift.

I am in the process of trying again and noticed tonight that at a certain point of the print, every time it hits the back right section I get this rattling noise (hopefully the video uploaded)

I’ve looked online quickly and only thing I could get a point towards what perhaps the steel bars being loose?

I would love some thoughts on whether others have experience with this or happen to know and can help to diagnose ? 

Sounds like chamber resonance which is common in the Core One. Two ways (that I know of) to mitigate it is:

1. Make sure the belts are correctly tensioned and the gantry is square with no play
2. Loosen the four screws on the linear bearing holder on either side of the gantry. Slide the gantry to the front and back several times then tighten the screws. 8. Assembling the linear holder left
3. Purchase the accelerometer and run the phase stepper calibration. 

Doing these things (for me) quieted the printer a lot. 

RE: Strange rattling noise

I'm not hearing anything alarming, but a recording can be deceptive. What it sounds like to me is that section of the part is busier and has a lot of bed movement. A lot of bed motion (ups and downs) is noisy: a lot of XY extruder jerks, three Z motors rapidly spinning alternate directions, the mass of the bed hopping up and down very rapidly... you get the idea.  

As for shifts ... the failed part might have melt marks where the head crashes into the part. That can offer clues to probably cause. Lacking that, did you slice with Avoid Crossing Perimeters set? 

Also, is this a kit printer or factory assembled? 

RE: Strange rattling noise

Many thanks for the insight I’ll take a look at these and report back (the accelerometer I’ve read a few times as a worth while investment)

RE: Strange rattling noise

That’s a fair point. It’s just the first time I’ve heard it and on the same print I’ve attempted 3 times (mind you I’m printing this one at 45 degrees)

it’s a kit build (my first) and interestingly enough it actually had ‘avoid curled overhangs(experimental)’ turned on for this one which greyed out ‘avoid crossing perimeters’ I think I’ve read that having this on can cause issues (both these settings) 

RE: Strange rattling noise

The Avoid Curling Overhangs setting causing issues is new to me, Slicer does so well to avoid making curls now it almost seems redundant. I think that if Avoid Crossing Perimeters is problematic, so is the other avoid setting; I'd certainly try slicing the part with both settings off.

Also, and I doubt this is your specific issue, if you have a volt/ohm meter, measure the resistance from the spade lug in the back left corner, under the extruder frame, to the X and Y motor cases (one of the screws holding the motors down should work).  If not zero, know that there is a known issue with static arcing causing resets that can cause shifts. My understanding is this usually happens on long bed length diagonal moves. Removing some paint and adding internal star washers to a screw holding the motors down solves it - easy 10 minute fix. 

RE: Strange rattling noise

I did initially have a minor issue with the cable from the filament sensor hitting off the Y axis as it moved to the back, but I still noticed a "tick" when the print head moved to the back - eventually I realised what it was - its the "arm" that the bowden cable is velcro tied onto hitting the back of the cabinet.