I have a fairly new P1S. About 400 hours used. It has worked decently for the most part. I just got done with a successful print. I went to go print another part and it made a loud groaning noise whenever the build plate / heat bed moves up and down.
I have cleaned and lubed the z-axis screws a couple times, and just did it again, thinking that may be the culprit. I cleaned all the other rods and there is basically no debris inside the unit. But it still makes the noise and will not allow me to print.
I checked the z-axis belt underneath and it is snug, and when moving the belt it still makes the noise. It sounds like it’s from inside the build volume area not the belt area. I removed the back panel and don’t see anything obvious.
Here’s some images of my machine in case anyone notices anything out of the ordinary?
Yes, the belt runs smoothly without any interference. Just the noise in the chamber. It doesn’t feel like it’s dragging anywhere. I’ve moved the bed all the way up and down using the belt. It won’t let me print either. It fails calibration.
One theory I might put forward is that one of the rod bearings may be defective or the base units may have shifted. Isolating which one can be the challenge.
Check this post regarding remedy for bearing rod popping out of the bottom of the P1 series. This is a quick check and quick fix if that is in fact what is causing this: Solution: The build plate is not placed properly
Here is another version of this problem but elsewhere in the travel path: Loose Bearing - #2 by Olias
It might help you isolate the problem but have you tried to use a sound meter app on your phone then hold the phone near each of the three lead screws and rods, both at the top and and at the bottom. Taking measurements or doing a simple recording and isolating where the sound is loudest might help in identifying the location of the noise. Then you can focus on observing that sections under a bright flashlight and see if you can notice any unusual screw or rod movement.
Here are two examples of apps that I’ve used to diagnose sound issues.
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Alternatively, you can pull a page out of the auto mechanics’ playbook for isolating noises inside an engine compartment. This method of noise isolation works for electronic motors too.
I used this auto mechanics stethoscope to determine the location of a faulty fan in one of my PC builds. With a PC case using five fans, it was very difficult to diagnose which one was causing bearing noise. This device has a contact rod option which allowed me to place the tip of the device right onto every fan housing and immediately hear which fan bearing was causing the noise. It would likely do the same if you placed the tip against each lead screw and bearing rod. You would hear any change in noise very quickly this pinpointing the location of any specific interference. Of course if it is a binding issue that is caused by plate misalignment, the noise may not be isolated but coming from all three locations. That too would be a useful clue.
Thanks. My bearings look like they’re in place OK. I might have to get that stethoscope. This is really annoying. I also put in a ticket with Bambu Lab so we’ll see what they say as well.
Thanks for the clear photos. Those bearings are exactly in place so that’s at least one theory put to rest.
One question that just occurred to me and was not evident in the video. Does this grinding noise occur at the beginning of travel, end of travel or all heights? Have you tried to manually move the bed height using the control panel and can you reproduce the noise? I ask because the control panel has an annoying quirk in that it does not move the Z axis uniformly, it does it in segments forcing the user to keep tapping the panel. However, in this case it may be useful. Alternatively, you can do this from the slicer which might be more convenient as mouse clicks seem to register more radipdly and more immediately than the panel button presses, but that could be more of a perception on my part.
The mechanics stethoscope is actually a great idea. Find out exactly where it is coming from. Great thought @Olias ! Once you have one, you find a lot of uses for it.
The lube you are using is good and the rods look like they are in good condition.
Also great to know the bed is level.
My next thought is to take the bed off and inspect the screws and bearings deeper. But that can be a little invasive.
Calibration should not make it worse but if let’s say the issue turns out to be a stepper motor that is on the edge of failure, it may push that component over the edge into failure mode. While that may not seem desirable at first glance, at least you would have a definitive diagnostic and repair path.
Thanks. Yeah, I wish I knew what it was so I could just fix it. Hoping Bambu support can shed some light, and hopefully provide me with parts (still under warranty).
It may be the motor. But if I send a job or send the home routine, it exhibits the groaing noise issue. If I move the Z-axis belt by hand, it exhibits the same groaning noise. If I operate it with the software it does not make the noise. The software would have to engage the motor as well I would think. So odd.
OK. I mis-read, not sure how (“I checked the z-axis belt underneath and it is snug, and when moving the belt it still makes the noise.”). I thought when you moved the belt by hand it didn’t make the noise. It sounds more like a parts interaction issue then. When you cleaned the build chamber did you see any small bits or powder like a belt or pulley was mis-aligned or any signs of wear on a belt edge?
I also put a little bit of lube on the z-belt idler pully. I moved the belt around and made sure everything was adjusted in the center of all the pulleys, but that didn’t seem to make a difference either.
I’m beginning to wonder if the belt skipped a tooth on one of the screws, causing it to bind. However, that is uncommon, and does not explain why the noise only occurs during homing.
If you look earlier in this thread, I checked that and provided photos. They all look OK. Despite that, I did do the upside down flip, move bed all the way to top of chamber, then pushed down with some pressure to make sure they were all in place.
Regardless, this machine has less than 400 print hours on it. Not saying they can’t fail in that timeframe, but unlikely, unless there’s a defect.
