RE: Reason for Core One rumbling found (?)
I want to add to this discussion with my observations related to excessive Z-axis vibration.
Z axis vibration is present regardless of motor speed and seems to be transmitted through the rear and right side z-axis threaded rods. The vibration is worse the faster the z-axis motors operation. The right side z-axis rod experiences severe vibration that results in noticeable wobble towards the bottom of the printer.
I have tried to eliminate possible alignment issues by loosing the z-motor mounting screws, the screws mounting the trapezoidal nuts, and the trapezoidal nut to hotbed mounting brackets, and then running the bed up and down to center the moving parts. When cycling the bed up and down with all these screws loose, there is very little vibrational noise. I then slowly tightened the screws while continuing to cycle the bed up and down a total of about 10 up and down cycles. there was little to no improvement when done.
During this sequence, I noticed that the vibration could be very effectively dampened by applying a slight centering pressure on the top of the right side z-axis threaded rod.
I also noted that with the bed at the bottom, the top of both z-axis threaded rods were making contact with the front of the provide holes under the carriage. With the bed at the top of the printer the threaded rods were in contact with the back side of the same holes. To me that indicates parallelism of the bed changes across the full range of the beds vertical travel. Possible because the back z-axis is moving at a different rate or the motor is slipping. This could certainly be causing the vibration. I have tried to resolve this but have not yet been successful.
RE: Reason for Core One rumbling found (?)
I want to add to this discussion with my observations related to excessive Z-axis vibration.
Z axis vibration is present regardless of motor speed and seems to be transmitted through the rear and right side z-axis threaded rods. The vibration is worse the faster the z-axis motors operation. The right side z-axis rod experiences severe vibration that results in noticeable wobble towards the bottom of the printer.
I have tried to eliminate possible alignment issues by loosing the z-motor mounting screws, the screws mounting the trapezoidal nuts, and the trapezoidal nut to hotbed mounting brackets, and then running the bed up and down to center the moving parts. When cycling the bed up and down with all these screws loose, there is very little vibrational noise. I then slowly tightened the screws while continuing to cycle the bed up and down a total of about 10 up and down cycles. there was little to no improvement when done.
During this sequence, I noticed that the vibration could be very effectively dampened by applying a slight centering pressure on the top of the right side z-axis threaded rod.
I also noted that with the bed at the bottom, the top of both z-axis threaded rods were making contact with the front of the provide holes under the carriage. With the bed at the top of the printer the threaded rods were in contact with the back side of the same holes. To me that indicates parallelism of the bed changes across the full range of the beds vertical travel. Possible because the back z-axis is moving at a different rate or the motor is slipping. This could certainly be causing the vibration. I have tried to resolve this but have not yet been successful.
RE: Reason for Core One rumbling found (?)
I want to add to this discussion with my observations related to excessive Z-axis vibration.
Z axis vibration is present regardless of motor speed and seems to be transmitted through the rear and right side z-axis threaded rods. The vibration is worse the faster the z-axis motors operation. The right side z-axis rod experiences severe vibration that results in noticeable wobble towards the bottom of the printer.
I have tried to eliminate possible alignment issues by loosing the z-motor mounting screws, the screws mounting the trapezoidal nuts, and the trapezoidal nut to hotbed mounting brackets, and then running the bed up and down to center the moving parts. When cycling the bed up and down with all these screws loose, there is very little vibrational noise. I then slowly tightened the screws while continuing to cycle the bed up and down a total of about 10 up and down cycles. there was little to no improvement when done.
During this sequence, I noticed that the vibration could be very effectively dampened by applying a slight centering pressure on the top of the right side z-axis threaded rod.
I also noted that with the bed at the bottom, the top of both z-axis threaded rods were making contact with the front of the provide holes under the carriage. With the bed at the top of the printer the threaded rods were in contact with the back side of the same holes. To me that indicates parallelism of the bed changes across the full range of the beds vertical travel. Possible because the back z-axis is moving at a different rate or the motor is slipping. This could certainly be causing the vibration. I have tried to resolve this but have not yet been successful.
RE:
Today, I tried to gradually counteract the resonance of several components.
The resonance was very audible during movements in the X-axis between 60 and 80 mm/s.
The more I tried to dampen it, the worse it became in the end compared to the beginning.
In between, I installed two alternative stepper motors from Stepperonline to perhaps achieve an improvement with phase stepping—no change.
Foam between the Nema and Nema holder or Nema holder and frame improved the situation around the source of the noise.
My conclusion after returning everything to its original state:
The excitation or source of why everything starts to vibrate is the Nema. Transmission via the pulley to the belt. The less vibration is transmitted to the frame, the more the belt gets. (my assumption)
In the end, the Nextruder hummed louder than at the beginning.
My personal guess about today's experiment: The phase stepping could be better and possibly eliminate the resonance.
I have been chasing the same sound issue since building my kit last July.
Just as a PSA to everyone, the QC on the motors they were originally shipping was terrible. Prusa have sent me replacement x and y motors and now the difference is staggering.
I did some simple tests on the motor using a rigid pendulum to demonstrate movement when not powered. I was able to show prusa support that they both required a large force to turn and also the steps were very jittery compared to control. Now that they are replaced everything is quieter, including reduction in the high pitch movements of the print head.
Along this journey they also sent new linear bears for both rods and replacement L brackets. (I was also having persistent homing issues). I have done all the other recommendations noted here and in other threads
All this said and done even with the reduction I still am getting vibrations from the bearings, mainly the left - X. Granted albeit it's no where near as bad. As shown by others if i push on the bearing during printing and noise it stops it. Also interesting its much worse when the printhead is at the back left quadrant. And there is near no vibration if printing something at the front right quadrant of the bed
I am very curious how well the foam helped between the stepper motor and pulling housing? You note you saw an improvement. I am considering maybe designing a thin TPU washer for this to just slightly dampen some vibrations. It would be more rigid than foam so hoping it wont impact print quality.
RE: Reason for Core One rumbling found (?)
I am very curious how well the foam helped between the stepper motor and pulling housing? You note you saw an improvement. I am considering maybe designing a thin TPU washer for this to just slightly dampen some vibrations. It would be more rigid than foam so hoping it wont impact print quality.
Not really. I had high hopes for it, but it didn't really do much.But that's what led me to the sliding bearings in the end.Even though everyone says I have the wrong rods for it and that without preload the play is too big—that may be true, but the printer is quiet and the print results haven't gotten any worse.
Mods for Core One: Core One HT 450 degrees, Comfortable display , Very fast print start and Reducing noises
Mods for Prusa XL: Very fast print start
RE: Reason for Core One rumbling found (?)
Did the sliding bearings have any effect on VFAs? Those are still the main annoyance with my Core One when I print decorative parts. (Or functional parts that will be looked at, like enclosures.)
RE: Reason for Core One rumbling found (?)
Did the sliding bearings have any effect on VFAs? Those are still the main annoyance with my Core One when I print decorative parts. (Or functional parts that will be looked at, like enclosures.)
When searching for the noise, I was initially only concerned with the noise itself. That is gone.
The VFAs did not improve after installing the sliding bearings.
On page, you can see that the waveform has the spacing of the GT2 pulleys.
On Reddit, I found a post saying that they fixed this with a larger pulley, including an adjustment in the GCode to compensate for the change in distance—that will be the next attempt.
However, this has just fallen back to second place on the list of important things to do. The high temperature issue in the Prusa Core One is currently bothering me more than the VFAs.
I want to experiment with layer adhesion to see the differences between 290 degrees and 350 degrees when using PPS, PPA, etc.
At the same time, I ordered a Volcano heating block because the space available in the copper block with the original dimensions is too small to store the PT1000 there and build insulation around it.
Mods for Core One: Core One HT 450 degrees, Comfortable display , Very fast print start and Reducing noises
Mods for Prusa XL: Very fast print start
RE: Reason for Core One rumbling found (?)
I am very curious how well the foam helped between the stepper motor and pulling housing? You note you saw an improvement. I am considering maybe designing a thin TPU washer for this to just slightly dampen some vibrations. It would be more rigid than foam so hoping it wont impact print quality.
Not really. I had high hopes for it, but it didn't really do much.But that's what led me to the sliding bearings in the end.Even though everyone says I have the wrong rods for it and that without preload the play is too big—that may be true, but the printer is quiet and the print results haven't gotten any worse.
Pity, thanks for your reply and for doing all this troubleshooting youve done. Very valuable. Feel like we need to set up some type of unofficial Core One wiki to consolidate some of this work! The forums here are a treasure trove of info.
RE: Reason for Core One rumbling found (?)
Feel like we need to set up some type of unofficial Core One wiki to consolidate some of this work! The forums here are a treasure trove of info.
I think this will be a process that requires a lot of helping hands.
Perhaps we will see the first signs of this in 2026 when the promised improvements are implemented?
Mods for Core One: Core One HT 450 degrees, Comfortable display , Very fast print start and Reducing noises
Mods for Prusa XL: Very fast print start
RE: Reason for Core One rumbling found (?)
I would think that Prusa could train an AI to handle a lot of the support requests. Or use an old-school, tree based expert system. Sounds like an interesting project for Claude... point it as this forum and have it digest everything into a Core One troubleshooting guide.