RE: Core One crash/restart
Can it be that this problem (zip tie in the middle on the x-belt) is our static electricity problem? Tomorow i will the motors grounded and cut the zip tie.
RE: Core One crash/restart
Hello, can static electricity build up if the belt rubs against a cable tie? In my case, the upper belt rubs against the cable tie that's attached to the fan bracket of the chamber ventilation system to hold the cable of the chamber temperature thermistor. It's directly above the center Z-axis. The core one is factory build.
This is why server rooms typically have a 42% humidity level; top prevent static build up / discharge.
RE: Core One crash/restart
Hello, can static electricity build up if the belt rubs against a cable tie? In my case, the upper belt rubs against the cable tie that's attached to the fan bracket of the chamber ventilation system to hold the cable of the chamber temperature thermistor. It's directly above the center Z-axis. The core one is factory build.
Short answer is 'yes', however the belt is not supposed to rub against the cable tie. In the build instructions Prusa specifically mention not to do this, i.e. ensure the tie is correctly positioned and tight enough that it doesn't rub against the belt.
RE: Core One crash/restart
Hello, can static electricity build up if the belt rubs against a cable tie? In my case, the upper belt rubs against the cable tie that's attached to the fan bracket of the chamber ventilation system to hold the cable of the chamber temperature thermistor. It's directly above the center Z-axis. The core one is factory build.
That can contribute to static charge buildup. But it seems likely that the belt can get charged even without that belt-to-plastic contact.
That cable tie in the back of the printer got quite some attention here during the early Core One kit-building days, and in most printers it did not touch the belts once the belts were tightened. Yet, the printer crashes upon fast, wide movements (with stepper motors that are electrically isolated) seem pretty common.
RE: Core One crash/restart
So Prusa did not work as there own instructions. It comes so from the factory.
RE: Core One crash/restart
You can clearly see wear marks on the cable tie. I can take a picture. But anyway, tomorrow I'll install flap discs (Fächerscheiben) and measure with a multimeter.
RE: Core One crash/restart
Here is a nice document to static electricity in belt driven systems. In German. Also is a lot of stuff to read in the Creality Forum about this problem. The only way to solve is grounding the steppers and use a powergrip gt2 "RF" belt that is antistatic version. We use here the higher temperature version "E" for EPDM.
RE: Core One crash/restart
The only way to solve is grounding the steppers and use a powergrip gt2 "RF" belt that is antistatic version.
For the Core One, it is apparently sufficient to ground the stepper motor chassis. User report consistently say that this resolved the "crashes upon long fast moves" problem, even with the standard GT2 belt (which is not the RF version). Maybe that leaves some residual charge somewhere on the belts, but if so, it does not seem to cause problems.
RE:
Could the problem be related to the new E-belts? Perhaps the modified rubber compound, designed for higher temperature resistance, generates more static electricity? As Breco states in their documentation, most static electricity is generated during the tooth engagement process in the pulley's tooth gap by friction. As far as I know, we never had this issue with the older machines, and they all use the old standard GT2 RF belt, although, for example, the MK4 doesn't have a grounded stepper motor.
RE: Core One crash/restart
I wasn't aware of a switch to Breco belts, my CORE One kit (from early 2025) uses Gates Power grip belts. I suspect most people reporting this were on Gates.
I think the reason it affects CORE series not MK4 series is the sheer length of belt, and now there are 2 belts! That's more than double the length for static to build up.
RE: Core One crash/restart
I, too, have experienced the crash/restart upon inserting or removing my smooth print sheet. It has never happened with the satin sheet, only the smooth. When I first received the smooth sheet, it would crash/reboot about every third time that I would remove/insert the sheet. Now, it happens about 1-in-8 times. I even have a video of it happening. Any additional info about fixing this would be great. I am very concerned that one of these times the entire controller is going to be fried.
RE: Core One crash/restart
Thanks a lot to all who where involved in fixing that problem.
I ran into that issue after 6 weeks using my printer without any problems.
It was the first time I printed a plate of 190x190 mm.
The printer rebooted several times printing the first layer leaving nice blobs.
I did not want to pollute my printer by milling the powder coating, so I went to a different solution which works fine.
I added two short cables to connect the motors to a definitely grounded screw.
The whole process took three hours, two hours for research and reading and one hour for fixing the problem.
I have printed four of the plates mentioned above without any problem.
Thanks a lot again!
Cheers
Ralf
RE: Core One crash/restart
I wasn't aware of a switch to Breco belts, my CORE One kit (from early 2025) uses Gates Power grip belts. I suspect most people reporting this were on Gates.
I think the reason it affects CORE series not MK4 series is the sheer length of belt, and now there are 2 belts! That's more than double the length for static to build up.
No no, the Core One uses Gates Powergrip GT 2 belts with the suffix „E“. This Version of the Gates belts is for higher temperatures. The dokument what i mean is in the link i posted and it is a investigation of the Breco Antriebstechnik Breher GmbH to static electricity in thoothed belt driven systems.
RE: Core One crash/restart
Are the holes in the stepper mounting plate threaded? I'm thinking of using a thread tap to clean out any poweder coating in the threads.
RE: Core One crash/restart
I, too, have experienced the crash/restart upon inserting or removing my smooth print sheet. It has never happened with the satin sheet, only the smooth. When I first received the smooth sheet, it would crash/reboot about every third time that I would remove/insert the sheet. Now, it happens about 1-in-8 times. I even have a video of it happening. Any additional info about fixing this would be great. I am very concerned that one of these times the entire controller is going to be fried.
Hi, it's basically the same problem as with the belts. Sometimes when I lift my smooth sheet and remove the print, it crackles like a balloon.
I just measured my Core One, and the print bed, or rather the entire Z-carriage, isn't grounded. If I remember correctly, I also had a crash like yours once.
RE: Core One crash/restart
I, too, have experienced the crash/restart upon inserting or removing my smooth print sheet. It has never happened with the satin sheet, only the smooth. When I first received the smooth sheet, it would crash/reboot about every third time that I would remove/insert the sheet. Now, it happens about 1-in-8 times. I even have a video of it happening. Any additional info about fixing this would be great. I am very concerned that one of these times the entire controller is going to be fried.
Let's see, I'll probably add an extra grounding cable via the Z carriage power cables and connect it to the metal of the Z carriage.
RE: Core One crash/restart
It is good people on the thread have worked out a fix for this but clearly this is a mechanical issue for purse as they are powder coating a critical interface which needs to be masked off prior to the part being powder coated.
I have seen this sort of thing many times in product development as from a mechanical engineer perspective this is makes no difference to the function of the part but saves a few cents, the reality is it creates a major customer problem.
The fact this is still happening months after it was identified, Prusa should be ashamed of themselves.
RE: Core One crash/restart
I'd love to hear from someone with a newer CORE One or especially CORE One L to see if it has been fixed in newer revisions. Seems like a tiny adjustment to the powder coating and possibly a washer are all that would be needed.
RE:
Prusa doesn't care. Their Customer Service is horrid. I have the C1L, I have brought them many issues and they just gaslight me. I even brought this static issue to them, they said yeah, its winter and dry, you'll have static, and that will happen, didn't care. The C1l crashes more than windows 95, don't care. The wire harness catches on the fan, don't care. The firmware has a bug that it will lose the Z, and then crash the nozzle into the bed. I can repeat the failure and prove it by video, been on chat 4 different times, don't care. The AC power bed won't work with a UPS, they did release a new firemware, didn't fix the issue all.
It is good people on the thread have worked out a fix for this but clearly this is a mechanical issue for purse as they are powder coating a critical interface which needs to be masked off prior to the part being powder coated.
I have seen this sort of thing many times in product development as from a mechanical engineer perspective this is makes no difference to the function of the part but saves a few cents, the reality is it creates a major customer problem.
The fact this is still happening months after it was identified, Prusa should be ashamed of themselves.
RE: Core One crash/restart
It was not fixed on the C1L
I'd love to hear from someone with a newer CORE One or especially CORE One L to see if it has been fixed in newer revisions. Seems like a tiny adjustment to the powder coating and possibly a washer are all that would be needed.