Sometimes one z-level is not printed

[robertbaruch 0]

I've experienced this three times. It doesn't happen all the time. When it does happen, I just print the same file out and the problem doesn't occur. Happens with both PLA and ABS.

In the image, note that the socket on the left has the missing z line, while the one on the right, which I reprinted, does not. I'm currently reprinting the box, so I don't have that to compare.

So, it can't be a problem with the file since I use the same file. It can't be a problem with the extruder or filament, because it's always exactly one z line, no sputtering, nothing that would indicate partial extrusion. It has to be a glitch in the firmware. I'm wondering if anyone else has experienced this, and if so, Ultimaker should probably look into it.

Edited January 16, 2016 by Guest

[Nicolinux 288]

Does it happen at the same height? If yes, maybe it is something with the filament that's spooled on the roll. A friend of mine had this too and the problem was a filament spool that was stored in a weird way where only one area of the spool was exposed to heat and light. On this area the filament was deformed and it lead to under extrusion in regular intervals...

[Nicolinux 288]

Btw. which printer do you have? The surface looks a bit unusual (or maybe it is the lighting) - or slicing. Do you use two shells when printing? (slicing setting in Cura).

[JohnFox 25]

Suspect it is the dreaded Z axis bearing problem that quite a few of us have hit.

In my case the bearings would periodically lock up, causing the missing layer. I eventually replaced the bearings but I think the underlying cause is lubrication on the Z pillars. Any oil on the pillars makes the balls slide, rather than roll and this causes the lock up.

Some time ago I tested this by oiling the pillars and the fault occurred. When I removed all trace of the oil the fault cleared and hasn't returned ( yet ).

Use kleenex to remove all lubrication from the pillars, move the bed up and down a few times and repeat the wiping.