RE: Reason for Core One rumbling found (?)
As a quick and (very) dirty alternative, you could just remove the screws and use a few zipties to hold the motor to the frame with some rubber bellow it 😆
I'll have to see if I have enough space. Joking aside, no, this solution is too simple for me 🙂
RE: Reason for Core One rumbling found (?)
A couple "armchair" comments.
When I try to do videos of my Core One, I pick up way more fan noise than anything else. The motion system, however, sounds like a decent stepper system and I don't hear anything rattling. IMO, you need to zero in on exactly what the mechanism of the rattling is.
I was looking into flexible filaments like TPU and did a small test print. I had never realized that TPU has very little elasticity and if you stretch it, it's stays stretched. What I really wanted was TPE (elastomer) filament. Should have some soon. That (supposedly) acts more like rubber, having a bit of stretch. I don't know about damping in either material, but damping converts energy to heat and is the best thing for killing vibration. That's how Sorbothane works. Sure wish we could print that! Further OT, if you're familiar with IGUS bearings, they also sell IGUS filament. Great stuff if you need to print something slippery.
RE: Reason for Core One rumbling found (?)
The motion system, however, sounds like a decent stepper system and I don't hear anything rattling. IMO, you need to zero in on exactly what the mechanism of the rattling is.
I agree. There are two ingredients involved in the resonant noises: Something needs to excite them, and something need to resonate, amplifying them in audible volume.
Jan's current focus is on the excitation side (from the stepper motors). A softer motor mount may help. But if not done yet, running a phase stepping calibration to obtain smoother micro-stepping might already go a long way? In this respect there seem to be differences between individual Core One specimens: Some stepper motors happen to be nicely symmetrical and run pretty smoothly without phase stepping optimization; others benefit significantly from it.
But identifying and damping the resonating component(s) may have a bigger impact. The sound in the video (parallel Core One L thread) with its harsh harmonics suggests that some part is rattling along. As mentioned, my first suspect would be the Nextruder covers or the fan shroud. Simply removing them for a quick test, with a print that is known to produce problematic movements/speeds, should confirm or falsify that guess.
RE: Reason for Core One rumbling found (?)
I have an untried suggestion. Placing lead free wheel weights on the frame in random places might dampen harmonics building up on that frame. Harmonics occur at 1/2 1/3 1/4 1/5 etc of the distance of a span, so you would want to choose the sites sloppily.
I was also thinking of stick-on foam window insulation on the frame and/or panels. People trying to quiet their computers used to do this, sometimes you see it in commercially built computers.
RE: Reason for Core One rumbling found (?)
It would be so cool to have a video from Stefan from CNC Kitchen going into the rabit hole on this subject!
RE: Reason for Core One rumbling found (?)
I have an untried suggestion. Placing lead free wheel weights on the frame in random places might dampen harmonics building up on that frame. Harmonics occur at 1/2 1/3 1/4 1/5 etc of the distance of a span, so you would want to choose the sites sloppily.
You can try by simply placing your hands on the frame in various locations during a print. That not only adds weight, but also damping. Healing by touch... 😉
I am skeptical though whether this will have a major impact -- unless there are also loose, rattling parts, in which case those should be fixated first. In recordings of undesirable noise in some Core Ones, I typically have not heard a low hum (as one would expect from large panels oscillating smoothly), but rather a sharp buzz (consistent with a part vibrating and hitting a hard stop).
RE: Reason for Core One rumbling found (?)
Here is my experience and solution of this problem.
I got the Core one as a kit in Apr2025. Right after the assembly it was running fine. A bit noisier than my MK4 but nothing disturbing. Since the beginning the Core one was on a concrete plate over a 5cm foam. I used that on the MK4 as well and this combination stops all the vibrations from going down to the cabinet, where it is placed.
After about 3-4 days total printing time (I did not print much and that means about 2 mounts later), I started getting this metal rattling sound during perimeters and gyroid infill printing and the noise was increasing every week. The printer is located in my leaving room and that became a problem. After some tests I found that this comes from the Y bearings. Slight press on the X bar was enough to make it quiet. Filling up the bearings with grease removed the noise as well, but just for 1-2 hours till they push the grease out. It looks like they have some freedom, and during resonance in X direction they just start ringing.
I was not a big fan of these bearings even on my MK4 and decide to switch to linear bearings. I ordered Hiwin MGNR12R rail with MGN12H, Z1 cartridges. As a link to the existing X-bar angles I had to mill such an adapter from a standard T-shape profile 35x35x3mm (used a CNC milling machine for that)
This is how it looks in the printer:
Because they are wider, I had to make a new, lower side filament sensor (had to make two versions because the CAD model was not available at that time):
Comparing to my MK4, where I was not hearing the X and Y motors (after I placed it on the concrete plate and foam), I can hear them on the C1. And this is because the enclosure. As I had to disassemble everything, I decided to place a 1mm silicon pad between the motors and the holders:
I did both changes at once and I cannot tell if this silicon pad improved something. At least it did not make anything worse. I know that flexible joint may cause quality problems, but I don't have such.
The result from this upgrade - I can still hear the linear bearings when they do fast movements during retraction, but during normal printing the loudest item is the Advanced filtration fan, which I limit to 75%. It stays 3m away from me and is working all the evening while we watch TV. No one complains.
The printer still resonates, but I can hear this only if I am right next to it. And maybe is correct to say "feel it".
Overall costs:
158EUR - Linear rails + cartridges. I was surprised how expensive they are. This was one of the reasons to pick this brand. THK, IKO are about double.
16EUR - 1 meter Aluminum T-profile
40EUR - XY Frame. Optional. To be sure that I will not down the printer for several days if I damage the frame, I ordered a new and drilled it in advance.
I managed to get a professional sound meter as well. From 1m distance I have around 40dB, which seem to come from the fan. The highest peak I measured was 52,8 during a fast movement.
I was concerned if the tight bearings may cause a problem at higher chamber temperatures. This all happened in October. Since than I have more than 100 hours printing mainly PETG and only few (5-6hours) PCCF. The printer is as silent as it was after the upgrade.
I don't know if I have a limit of the files I can upload but will try. Here is a short video. The background noise is the filtration fan, which can be used as reference, as the phone makes everything much noisier as it is:
RE:
This is an excellent mod! Could you make it available on Printables? I don't have access to a CNC to make the brackets and would need to send off the CAM files and have JLPCB/PCBWAY etc do it.