Print stops randomly

Had this happen on my Sanguinololu setup earlier. I have now taken out the DTR 0.1uF capacitor so the USB cannot reset the Atmega during normal printing (the capacitor can be replaced for firmware flashing). Will report back after much testing.

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[emaker.io]

[emaker.limited]

I am also experiencing this problem.

My details:

When i first built the printer i did not seem to have this issue.

My issue seemed to start when i plugged a monitor into the printer during a print. I saw a spark to the metal part of the HDMI cable, and at this point the printer froze. Using rep-snapper the RAMPS was unresponsive. When I grabbed the USB cable to unplug the RAMPS i noticed it was HOT. I immediately unplugged every thing. It had gotten hot enough to start melting the jacket of the cord.

I went through a processes of trying to see what was damaged. I could not find anything. I did cut the diode out of the RAMPS board. It was oriented the right way, but that was the only place i could figure excess power could have been back feeding into the computer (and I assume out the ground of the monitor).

my symptoms are:
Printer will stop randomly
i will some times get 20 min into a print, sometimes it will be 2 seconds.
Pausing and un-pausing rep-snapper will get it going again (but that means i need to stay there for a whole print.)
I also get junk (random characters) in the error window in rep-snapper.
The random characters look exactly like what i have seen when a serial message gets corrupted, or two serial devices try to communicate at different baud rates.


I have tried:
Useing various length USB cables getting ever shorter
I have dug out all my best quality USB cables
I have stepped down the speed to 57600 to give my self a better chance of a readable signal
I have used other devices (Mice, Keyboard, Hard drive) in the USB port where the incident occurred with no issues
I have used the various USB ports around the laptop

Nothing has worked

I am going to try:
A different laptop (USB port seems fine, but its worth a shot.)
I am going to look into using a FTDI to talk to the mega and bypass the built in USB port.
If all else fails i will buy another MEGA and hope

I realize my problem is most likely due to damage i caused, but it still sounds related to what others are facing.


Has anyone else noticed random junk in the com window of rep-snapper? Does pausing and un-pausing rep-snapper work for most people?

Your problem is definitely electrical. At least the melting wires part of it.

This subject of printer freezing probably needs to have a troubleshooting page on the wiki. There are many things that can cause freezing.

Temporary Freeze:
1. Windows Update
2. Anti-Virus Running
3. Running Skeinforge slicing while printing.
4. Underpowered PC with too much going on in the background.
5. Wrong Skeinforge settings - This causes short pauses
6. Bad G-Code - Needs the KICK button in Repsnapper to start back up

Permanent Freeze
1. Running other high-drain USB device on same bus - Web Cams, and such
2. Plugging in a USB device while printing
3. Having a weak connector on the USB cable
4. Having a ground loop where RAMPS and PC are being powered from separate circuits at the circuit breaker panel.
5. Running a microwave oven or stove, or refrigerator on the same circuit

Theoretical but need to be proven:
1. Noise generated by stepper motors - I don't buy this one
2. Cheap USB cables - My cable was free, and works fine, and is really cheap looking.
3. Dell Computers - I think there might be something to this one.

Feel free to add to this list. Anybody know a good place to put this on the Wiki? Like is there a troubleshooting index?

-Wildseyed-

Watch out for electrical noise on your Endstops, this can be a big problem and can cause your machine to get really messed up, they are basically nice little Ariel's that will pick up electrical noise and pass them onto your electronics causing all sorts of confusion in your firmware. keep them short, keep them away from the Power input or switching power outputs and run the cables separably, not in a bunch with all your other cables.

While running your machine - Don't run mains things that have motor's in them (Angle Grinders, drills)

In my experience with development of USB based products I have seen many situations where the cable was at fault. There are many USB based Micro's that have issue with the quality of USB cables / USB connectors even if they are only enumerating to be an RS232 serial port or other basic HID device.

Even with Reprap developments I have 2 USB cables (2m and 3m long) that cause comms errors on two different MEGA's One was not cheep and the other is USB2.0 rated so it's not just about the cost or length.

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[richrap.blogspot.com]

I think I "broke" my machine. Now that it is broken it is showing very similar behavior to others. I hope that I figure out what broke on mine it might help others that are suffering.

I did a quick test last night. I unplugged my ramps board from the mega and ran a print. The problem resisted with nothing but the mega powered or plugged in.

I have some screen shots at home of what rep-snapper looks like when I get the error. I will try to post them later.

I had a huge issue with the end stops. It occupied most of my 4th of July weekend. After I twisted the end stop wires that issue went away.

I'm also experiencing the temporary version in RepSnapper ("Kick" gets it going again) and permanent pauses using pronterface (I have to close and reopen the connection to the printer to get going again)
I'm not sure why it's happening but I just noticed something very unusual.
During a print (in RepSnapper) if I click/drag on the 3D rendering to move it around, the print halts while I'm dragging and starts up again immediately when I stop.
I guess that would be problem 4 under temporary freeze. I'm going to get an externally powered USB hub and see if that helps. I also plan on trying my Wife's Mac (I'm using a linux laptop).
I've been printing successfully with this problem for a long time, but it's still annoying. I deal with this issue by setting up an auto clicking program (I use xAutoClick) to click the "Kick" button every second throughout the print. It's an ugly hack but hey, it works!

You can also install a diode in the RAMPS board to supply the Arduino. I understand that as long as your power supply to RAMPS is 12 V, then it should be fine. The recommended input voltage for the Mega 2560 is 7-12V and the limits are 6-20V.

jcabrer Wrote:
-------------------------------------------------------
> Your problem is definitely electrical. At least
> the melting wires part of it.
>
> This subject of printer freezing probably needs to
> have a troubleshooting page on the wiki. There
> are many things that can cause freezing.
>
> Temporary Freeze:
> 1. Windows Update
> 2. Anti-Virus Running
> 3. Running Skeinforge slicing while printing.
> 4. Underpowered PC with too much going on in the
> background.
> 5. Wrong Skeinforge settings - This causes short
> pauses
> 6. Bad G-Code - Needs the KICK button in
> Repsnapper to start back up
>
> Permanent Freeze
> 1. Running other high-drain USB device on same
> bus - Web Cams, and such
> 2. Plugging in a USB device while printing
> 3. Having a weak connector on the USB cable
> 4. Having a ground loop where RAMPS and PC are
> being powered from separate circuits at the
> circuit breaker panel.
> 5. Running a microwave oven or stove, or
> refrigerator on the same circuit
>
> Theoretical but need to be proven:
> 1. Noise generated by stepper motors - I don't
> buy this one
> 2. Cheap USB cables - My cable was free, and
> works fine, and is really cheap looking.
> 3. Dell Computers - I think there might be
> something to this one.
>
> Feel free to add to this list. Anybody know a
> good place to put this on the Wiki? Like is there
> a troubleshooting index?
>
> -Wildseyed-

Of course a firmware crash will add to the permanent freezes, at least my reprap will not continue after one.

I think a overloaded psu might cause temporary freezes, when a heated bed switches on. Probably having something to do with connection problems.

Also a permanent freeze is when the host software is on GCode line x and the firmware is on line y. This sometimes leads to a infinitive amount or error saying something like "line number is not ... "

I think the host software should timeout after x milliseconds and retry the previous GCode. That will solve most of my problems probably.

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reprapworld.com
PLA, ABS, PETG multiple colors (3 and 1.75 mm) €16,49 / kg
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Sorry to resurrect an old thread here, but I wanted to get my solution in here for the next person who searches on this issue.

I had this "random printer freezes" problem after tidying up the area where my printer is. It looks like I introduced the problem when I stood my power supply on its side and inadvertently blocked the fan. I suspect that it may have been overheating and as a result causing inconsistent power.

Since I've unblocked the fan this morning, I've been getting good prints again, so hopefully that was in fact the problem.

Original symptoms: After I had originally blocked the fan the day before, I got one good small print, but then every print after that failed by simply stopping at some random spot. I also started to notice slight hesitations from time to time while printing. Once it stopped completely, though, pronterface would freeze and none of the buttons seemed to work. The only way to get the printer working again would be to unplug and replug the USB cable. When I unplugged it, pronterface would output a list of exceptions, along the lines of "Can't read from printer (disconnected?)." I ruled out gcode by observing the problem on a print that was previously successful. My equipment is Windows > slic3r 0.8.3 > pronterface Mar2012 > Sanguinololu 1.3a > Sprinter > 30A PS, MKI heatbed, j-head IV-b.

Another one with the same problem. I was printing a very nice Venus and it was almost a perfect print when the printer stopped... In that moment I was not able to find a pattern.

However, today I was doing another print (2 hs so far) and I left the room, turned of the lights, and when I came back I turned on the lights and kaputt... print to the garbage...

Then I've found this thread... I have some electronics knowledge and I definitely agree that a kind of electrostatic charge is affecting the motor controllers (should be the motor controllers, because the combo Arduino-RAMPS is still controlling the temperature).

My conclusion is that this electrostatic charge is getting into the boards, affecting the motor controllers.

The question is how to stop it... I will start putting a metallic case around the boards... and adding a SDRAMPS as a second step to avoid using the USB cable.

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##diegudio##

I had same problem when print from virtual box with windows XP. I tryied to change configuration of USB hub uncheck "sleeping" of usb, but it doesnt help. After moving to virtual box with Ubuntu, the problem with print stop is gone. Even with longer cable.