U2 Bed driven into the head

[mikey 0]

I'm not sure where to post this because it is not a cura issue, but my U2 just drove the bed into the print head and would not stop. I had to power the machine off. It occurred when after aborting a print the material was retracted a lot, and I went into the settings option move material. Then as I was moving the material towards the head the bed began to move. It kept going straight into the head. If the head was not there I think the bed would have come off the threaded rod. This is on the latest 13.12 firmware. Just a warning for everyone else. It appears the printer is fine, but it was scary.

 

[gr5 1,931]

Very strange! Sounds like a software bug to me. It would be nice if you knew how to duplicate it (with your fingers on the power button of course!)

 

[illuminarti 18]

It's not a general problem with the 13.12 firmware, because I was jsut testing the abort/retraction bug, and so was using the move-material option extensively. Several times I accidentally clicked out of move-material mode, but I never had the bed do that.

 

[gr5 1,931]

There is a "direction" signal that runs from the arduino to the stepper driver. If that pin has a cold solder joint it could move the Z axis in the opposite of intended direction occasionally. So it *could* be hardware.

 

[mikey 0]

I think I was able to reproduce the problem. Sometimes when aborting a print, it will continue with a few more steps in the gcode before it cancels. If you are able to go into the menu and move material setting while the bed is moving down into the home position from the aborted print, the bed will start to move up and not stop. I can be hard to replicate depending on how fast your u2 aborts your prints

 

[illuminarti 18]

Ok, that sounds like it could be another side effect of how the abort code is currently working. I'll see if I can reproduce it as well.