Cura strange printing error

[MTG 8]

Hi,

I was printing a housing when this happened:

https://drive.google.com/file/d/1xeIf1RU8wTKBekbVRKasV_rwXLKBobR1ww/view?usp=sharing

 

When you look through the gcode, it's seems okay. The Z Values appear in the right order without the gap . Why does it do that? It's an 10 hour print ant it was all fine for like 7 hours and then this started?

And why does it go back don again for the wall?

Is it an Octoprint Error?

The simulation in Cura does not show this behavior neither, I have checked this.

 

Printed with Cura 3.3.1. My Gcode and Settings file attached.

 

Edit: okay, for every island it does liek a z-hop without going down. On the layer change it goes back to the correct layer. I can't figure out whats wrong here

 

profile.curaprofile

CFDMP_Gehause_Oberteil.gcode

Edited July 10, 2018 by MTG

[kmanstudios 1,120]

For that tiny island of material being printed, I would say that the speed is too fast for that one area. Try slowing down the print speed.

[MTG 8]

The problem is, that z is raised for the islands. In the gcode, there is no z lift at this pint. The printer did it anyways.. The only question is why

[gr5 1,933]

So you are saying the bed moved down suddenly for no apparent reason?  The Z stepper driver can overheat.  This is a known problem on the UM2 which was fixed by lowering the stepper current to I believe 900ma.  Some versions of Marlin let you edit this - look in motion controls and see if you can lower the Z stepper current.  If your version of Marlin doesn't make this easy to do there are gcodes to do it or you can install tinker Marlin.

 

You can test that this is indeed the problem by putting a 5kg weight on the back of the bed and seeing if it is even worse.  Basically the stepper driver turns off for about 1 second.

 

Or you can remove the bottom cover, tilt the printer with a dictionary/book and use a desk fan to give a little air flow over the circuit board.

 

[eldrick 64]

After noting overheated browning of the board in the area around the drivers, I drilled 3/4" holes in the electronics board shroud - one under each of the driver chips.
I also drilled some smaller holes on the sidewalls of the shroud to allow for flow-through ventilation.

Edited July 10, 2018 by eldrick

[MTG 8]

13 hours ago, gr5 said:

So you are saying the bed moved down suddenly for no apparent reason?

 

If you look at the video, this is not 100% accurate. It did move down, but its every time another island is printed. I think the printer did it "intentionally", because its every time a "z-hop" would be performed, if the option was activated (which I didn't). It looks like a z-hop, but the bed does not go up again. And it also looks like the z-distance icrease is always the same. I think you can even hear the servo doing that. I'm running with octoprint on an raspberry, I don't know if octoprint gave the wrong commands... but why after 5 hours