Printer freezes during mid-print, but can be started again by disabling steppers

[nick-foley 5]

So, as the title says, our Ultimaker occasionally freezes mid print. It stays at temperature, and stays turned on, and nothing in the Ulticontroller changes - but the print head stops moving.

We are printing from a Raspberry Pi, and so my initial assumption was that the client on the Pi had crashed, and I'd been trying to debug that.

However! Today we discovered, inadvertently, that if we use the Ulticontroller to "Disable stepper motors" while the printer is frozen, the printer starts working again. It then finishes the print without issue.

This makes me think it is related to the stepper motors or stepper boards overheating.

Is there any indication given by the Ulticontroller when the machine shuts itself down due to an overheated stepper board?

 

[gr5 2,192]

Printing through USB seems to have lots of trouble for lots of users of many operating systems. Because of this most people recommend printing only using the UC. But one person did mention that when they bought a powered USB hub all their USB printing stalls stopped happening. I have no idea why. Maybe it was just a bad USB cable? Or better grounding of the USB cable?

 

[mgg942 0]

Some degradation or loss of the signal, I expect. I've certainly experienced issues with other USB devices that won't work if connected to the computer USB port via a cable but will if plugged directly into the port. The powered hub may start with a stronger signal and thus better stand the losses in the connecting cable.

 

[xxgiuseppexx 0]

I had the same problem from my laptop. I used another laptop, turned the internet off, and went on to print something for six hours. No issues were encountered. I would say its computer related. People have switched to using a ulticontroller and have never seen the problem since.

 

[adeptusone 0]

I have the same problem now, but I'm using ulticontroller. It switches to card removed in midprint and stops.

 

[gr5 2,192]

I have the same problem now, but I'm using ulticontroller. It switches to card removed in midprint and stops.

 

Ouch. Does disabling the stepper motors fix the problem?

I have never had this problem but it's probably bad contacts. You could clean both the card and the contacts inside the UC. I think rubbing alcohol (isopropyl alcohol) might be a good cleaner. Be gentle - you don't want to remove the amazingly thin layer of gold plating on those contacts.

 

[SandervG 1,521]

You could also check the flat cables of your UC, i once saw one of them teared up and it resulted in it not being able to read the SD card. Maybe it is not teared up yet, but maybe it tangled up, or just broken inside?

 

[adeptusone 0]

Thanks for replies

This is not a problem anymore, a solid click of mem.card inside Ulticontroller solved this issue =) But also reinserting the card while this happening and hitting continue print sometimes solves this =)