Prints stop—can't see why.

I have a large object that I've printed several copies of, it takes about 5h to print, I've printed four of them so far. Sometimes, the print will complete seamlessly, but sometimes the print will just stop. Repetier won't crash or be frozen, I'll still be able to click buttons and navigate menus, I can pause and unpause the print, but nothing will happen. The bed, extruder, and fan will all still be on. It will still show me the X Y and Z coordinates, but the coordinates won't be moving, they'll be staying the same and the printer will be motionless. My solution is, as the Z coordinate is still displayed, I'm able to simply reboot the computer and printer, then chop off the front of the gcode—everything before the Z coordinate that was Repetier froze at—and start again from the layer that it left off at.

If I hit Kill Print or Emergency Stop without rebooting the computer and the printer, I'm unable to connect to the printer or restart the print. It's not a gcode problem, because it happens at random times throughout the code. Sometimes it happens, sometimes it doesnt.

When it's frozen, everything on the screen looks normal, except the coordinate values aren't changing, and, it isn't somehow becoming paused, as there's no 'resume' window, and I'm able to pause and unpause it when it reaches this frozen state, to no effect.

This problem happens occasionally on all of my prints, not just this one.

Just happened again, fourth time in a single print. New record! I check the print status and it says "running ..." it still gives me an ETA of 10m, despite not moving.

I tried closing and opening the program and turning the printer off and on, but when I do that, Repetier crashes when I hit the connect button. I have to turn the computer off and on before I'm able to connect to the printer.

Using ubuntu 14.04

Sounds like the usb connection gets broken by crashing the driver or something like that. That is also the reason reconnect/emergency stop can not work - communiction with usb->serial does not work any more. It seems that the usb serial converter is more sensitive to electrical problems then the main printer cpu. Try to stabilize your printer voltage e.g. by using actively powered usb hub. Check your usb cables are not near inductive sources like heater/motor cables.

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Hi Kre8, I am getting what looks like the exact same problem, not all the time but it has happened enough to me.

I have been trying to analyse this every time it happens, so far I have found the following:

1. There is nothing in repetiers log to indicate an issue, the last command is sent and then there is nothing.
2. On every time that this has happend I have found that the heaters are off but the stepper motors are still armed (as in you cant move them by hand). I suspect that merlin FW times out and switched off the heaters.
3. Removing as reinserting the USB cable on the PC resolves the issue.
4. Rebooting the PC (without rebooting the Arduino board) also resolves this issue.


From my observations above it looks like the Ardunio board is still running and the hang is not on it's side, if it happens again I will try resetting the Arduino board and see if that recovers it. If this is the case then it is good because at least that means that the heaters are still being regulated and I will not get thermal runaway.
Last night I switched to another laptop, I will try that again and see if this resolves the issue (ie there is an issue with the PC I am using's driver). I also would like to try using a slower baud rate like 128000.

Also going off repetiers suggestion I will see if I can try to power the Ardunio from the power supply and not from the USB (nned to do this anyway as I am waiting for a LCD screen in the post).

Kre8,


Since changing the laptop that I was using I have not seen this issue at all, I assume on my side this was the PC. I plan on reinstalling windows on that PC in the near future.

I have experienced something similar - in my case, I think it's static electricity. My PC's USB ports are very sensitive to it, and occasionally the PC can shut down when I insert a USB plug (the carpet in the room is synthetic fibre, and sometimes I can get small sparks off anything, including the wife!).

I have had prints stop when I've touched the metal frame of the printer... now the UK weather is moving towards summer and the air's a bit more humid the static is reducing.