Layer Shift after 7 hour pause

[Julian2801 1]

Hey. 

 

I'm having a bit of trouble when I'm pausing a print over night (due to long print times and I can't really sleep with my printer printing 6 metres from my bedroom). 

 

When I resume the print in the next morning there often is a 1mm offset to the right from the old and the new layer. Can I do something against it? 

 

 

Edited September 9, 2018 by Julian2801
fixed typo

[kmanstudios 1,120]

what printer?

 

Although I never have paused that long and would not to test just to test.

 

 

[Julian2801 1]

34 minutes ago, kmanstudios said:

what printer?

 

Although I never have paused that long and would not to test just to test.

 

 

It's an UM3

[kmanstudios 1,120]

Hmmmm, ok....I wonder if something is knocking the plate over a bit.

 

When the printer goes into pause, it homes the printhead to the front left (from facing the printer) and then goes to the back right. Is there anything like that, that you see when resuming?

 

[gr5 2,189]

The bed stays hot the whole 7 hours, right?  Because you don't want the bed to cool - if it does the part will likely come loose enough to look like a shift.

[kmanstudios 1,120]

2 hours ago, gr5 said:

The bed stays hot the whole 7 hours, right?  Because you don't want the bed to cool - if it does the part will likely come loose enough to look like a shift.

Would that not happen during a long term print? Why would the printhead sitting still while the buildplate is hot be different from regular long term printing?

[Julian2801 1]

14 hours ago, gr5 said:

The bed stays hot the whole 7 hours, right?  Because you don't want the bed to cool - if it does the part will likely come loose enough to look like a shift.

Yeah, the bed stays hot during the pause. I will try it again and see if it will happen again. Maybe I was just unlucky....

[tinkergnome 927]

Another possibility:

 

Someone in the German forum mentioned recently that there may be a firmware bug. He said that there's an offset of the print position after resuming - depending on the active print core. There where no details about which axis or by which amount though... He just said, the pause function on the UM3 is useless for him because of this.

If you use both print cores and if it is reproducible, you discovered perhaps the same issue?

 

Source: https://community.ultimaker.com/topic/24343-2-düsen-2-layerhöhen/?tab=comments#comment-218498

[kmanstudios 1,120]

I have not noticed this on my machines. And I have paused on both printcores for various reasons.

[Julian2801 1]

 

It looks like this for me after every pause longer than 2 hours... 

[gr5 2,189]

Is it a layer shift for sure?  or just an underextruded layer?  An underextruded layer would make more sense as it was dripping for a while - you could lift the lever on the feeder and slide some more filament in just before you start - but not too much or it will overextrude I think.  For normal loading of filament I slide it in until it stops then back off about 1cm.  Not sure how much to back off on a "resume" as I've never tried it on a UM3.

[Julian2801 1]

34 minutes ago, gr5 said:

Is it a layer shift for sure?  or just an underextruded layer?  An underextruded layer would make more sense as it was dripping for a while - you could lift the lever on the feeder and slide some more filament in just before you start - but not too much or it will overextrude I think.  For normal loading of filament I slide it in until it stops then back off about 1cm.  Not sure how much to back off on a "resume" as I've never tried it on a UM3.

I‘m sure that this is a layer shift because the following layers stay like this the whole print without going back to the „normal“ position.

Edited September 11, 2018 by Julian2801