Horizontal layer lines (Z-Banding?) - Assembly and first prints troubleshooting

RE: Horizontal layer lines (Z-Banding?)

Aaron O — Fri, 18 Jul 2025 17:44:25 +0000

Even though this is an old thread and the OP resolved the issue by replacing the heatbreak, I just wanted to add that horizontal banding can also result from wear of the hotend PTFE tube. I find that after 200-500 hours of printing (printing only PLA on a MINI), the inner tube at the hotend side of the PTFE tube becomes slightly dilated (expanded) and that this small defect is enough to affect under/over extrusion in certain instances. Here's an example:

The bands are usually regular in Z height and alternating. They often don't occur in the same layer where there are organic (or perhaps other) supports (perhaps because printing the supports "clears" the nozzle and equalizes the pressure variation that would otherwise cause under/over extrusion).

The fix is easy: just flip or replace the hotend PTFE tube. If the PTFE tube is new, you can flip it upside down since the opposite end will not be deformed/dilated. Since the same tube is the same length, you don't need to do the special tightening step. If you've already flipped the tube once, both ends will have wear and you'll need to replace the tube.

I usually flip or replace my hotend PTFE tubes about every 200-500 hours of printing or when I notice horizontal banding.

RE: Horizontal layer lines (Z-Banding?)

tompjagiello — Fri, 02 Dec 2022 15:10:43 +0000

Yes, I've gone back to the original Prusa heatbreak and all issues went away. Previously I was using a replacement from Bondtech and from my measurements the tube inside was slightly too short, thus causing uneven extrusion and print issues.

RE: Horizontal layer lines (Z-Banding?)

seackone — Fri, 02 Dec 2022 11:36:30 +0000

Is there anything new to this topic? I have exactly the same issues.

RE: Horizontal layer lines (Z-Banding?)

tompjagiello — Fri, 11 Dec 2020 14:03:05 +0000

@bdudelsack did you ever get this resolved? I'm battling the same issue and already looked at belt tension, greased rods, disassembled and cleaned the extruder and it's still there. One thing which seems to help is tightening the idler inside the extruder so it puts more pressure on the filament as it's being fed in, but I'm getting the feeling this is just a workaround rather than the actual issue.

RE: Horizontal layer lines (Z-Banding?)

F.L.A.M — Fri, 27 Mar 2020 21:49:07 +0000

My printer bed was a bit dirty when i printed those cubes, but it's clean now. I've changed the nozzle like it was described by E3D.

I've managed to find out that the ugly lines only come when i have infill. Whithout the infill the print is looking good. Right one is with 15% Gryoid infill.

RE: Horizontal layer lines (Z-Banding?)

Neophyl — Fri, 27 Mar 2020 11:09:38 +0000

If its being pushed out equally all around on each layer (which is hard to tell from the pics) then that would suggest uneven extrusion. Its very unusual for the z axis to be out. The rods are fixed to the motors on the mk3, no couplers to come loose. Although you could check that the dust covers aren't too close to the motor and binding. Some people screw them too far down when assembling the printer.

When you replaced the nozzle did you follow the E3d procedure exactly ? Even the tiniest gap between the nozzle and heatbreak (which meet inside the heatblock so you cant see it) can lead to uneven pressure and so extrusion artefacts.

I also notice that your bed adhesion sucks as the bottoms are bowed up away from the bed. There are many threads on here about the proper cleaning procedure but they all boil down to cleaning with unscented dish soap (fairy/dawn) and plenty of very hot water and then not touching the bed with your fingers. Works much better than even IPA. Considering that you are printing PLA onto a smooth sheet I would expect the bottoms to be stuck perfectly flat to a clean bed.

For example

That might be contributing to the extra squish at the lower layers as the layers are moving up as its printing but I would expect that to have evened out as the part progresses upwards.

RE: Horizontal layer lines (Z-Banding?)

F.L.A.M — Fri, 27 Mar 2020 10:49:49 +0000

Posted by: @neophyl
Its not the z axis you need to check its your x and y axis.

The lines go equaly over the complete perimeter of the model. If it would be X or Y axis wouldn't it be seen only on two sides? At the moment it looks like the fillament gets unequally squashed so those lines appear.

RE: Horizontal layer lines (Z-Banding?)

Neophyl — Thu, 26 Mar 2020 22:24:46 +0000

Its not the z axis you need to check its your x and y axis.

Horizontal layer lines (Z-Banding?)

F.L.A.M — Thu, 26 Mar 2020 21:01:54 +0000

Hello,

I'm trying to improve the printing quality and get rid of irregular layer lines. I've already did following steps:

* Cleaned, lubed and recalibrated the z-axis

* Recalibrated the PID

* Recalibrated the esteps

* Tried different filaments (white - h AmazonBasics PLA, grey - Prusament PLA)

* Replaced the nozzle and recalibrated everything.

What else can I do? Or is it the best quality I can get?

Printed in 0,15mm layer height in Prusa Slicer with stock profile.