My J1 often pauses during a print - as in it will be printing away quite happily, then the print head stops for sometimes up to 5 seconds, and then carries on.
This is bad enough when printing via Octoprint, but when printing from printer memory (ie started via the touch screen), I have seen it pause every couple of seconds, so I just have to cancel the print.
I am pretty certain that this is the cause of layer shifts on my prints (I have just started recording all prints on an old phone, but have only done 2 prints so far and have not caught a layer shift) - I am pretty certain that what is happening is that when it pauses, filament keeps on oozing out of the print head, and then at a later point the blob gets caught by the print head, causing a layer shift.
I typically print flexibles, so I have been OK until this point, but I am now printing a lot of PLA for a project and I am seeing >50% of prints have a layer shift, rendering the part un-usable.
What slicer are you using by chance?
PrusaSlicer
Here is a sample GCODE file that is exhibiting this issue
J1_XYZ 20mm pipe 2mm walls 20if solid traps 67.57g PLA.gcode.zip (5.1 MB)
And when you break down the slice layers VS cooling time where is it pausing in relationship to the print? Also what are your setting for your filament set at, and is it only a single head or they both do it? Last addition: if you slice it in Luban does it also do it?
With the print attached above, it always happens simetime around layer 180 (But not exactly on the same layer)
I tried printing this part in mirror mode once, and it happened. I forget which model it happened in.
Layer shift is sometimes in X, sometimes in Y.
In terms of when it happens in the print, the last time I printed this part it happened at 17:40, 33:00, 33:14, 39:25, 44:20, 1:47:30 and 2:46:10, although it probably happened more but I did not notice