How to Fix Z Banding

Z banding is a periodic pattern in your 3D printed layers that often resembles a bumpy ribbing look. It gives your prints an unpleasant look, rough texture, and reduces the bonding strength between the layers. Are you experiencing Z banding? Never fear. We have highlighted some of the main causes of z banding and how to fix it.

Resistance from the spool causing Z banding

This error is perhaps the most common cause of Z banding, and it happens when there is resistance from the spool pulling against the extruder, which then lifts the extruder up. In this case, the filament will pull until there is enough force to pull it loose, and then the extruder will fall back into its normal position. This is repeated over and over to create the Z banding.

What you can do:

• Run your filament through a low-friction tube or fixed structure from the extender to the spool. What you choose doesn’t have to be as low-friction as a Bowden tube, but it needs to be loose around the filament as to not increase friction. You can pick up a cheap and readily available 0.17 inch HDPE tube at your local Home Depot that will work just fine for this purpose.
• A Capricorn tube is a low friction bowden tube to help you with this. You can find one HERE. 

Lead screw wobble causing Z banding

Z banding can also be caused by your lead screw being misaligned, and this can lead to Z banding that directly matches up with the thread of your lead screw.

But what if my lead screw is already straight? If you have verified that your lead screw is straight, but you are still getting the Z banding, you are really having an issue with your coupler. The fix for a bad coupler is simple, 3D print a new one. In order to do this, you need some calipers and some sort of CAD software to model in. Novice Expert on YouTube has a wonderful tutorial that goes over how to create your own coupler to fix Z banding, and you can find the tutorial here https://www.youtube.com/watch?v=iBjzdw8DWuw].

Your filament diameter should be uniform so that there is not any variation in how it presses against the drive gear or how fast it feeds. Nonuniform filament diameter can cause inconsistent extrusion, so it is important that you ensure your diameter is as uniform as possible. Some low-quality filaments even have bubbles down the center, which will impact the cross-sectional area of your filament. 

What you can do:

• Sample the filaments of new suppliers before purchasing large batches of filaments.
• Check the tolerance ratings of the filaments that you buy. A tighter tolerance will lead to a more uniform filament diameter.

Inconsistent temperature causing Z banding

Temperature swings, even small ones, can lead to Z banding. These temperature shifts can cause some layers to spread out more than other layers due to the fact that they are extruded too soft. Sometimes even your platform will expand and bow as its heats, and that is enough to impact the layer height and cause Z banding.

What you can do:

• Complete your prints in an area that remains at a consistent temperature.
• Ensure your printing temperatures are as uniform as possible.

Irregular variation in layer height causing Z banding

Irregular variation in layer height is caused by the extruder platform or the extruder not maintaining the proper height while you are printing. On a cantilevered Z axis, this can be caused by wire binding or pulling. In that case, the resistance will cause the axis not to move enough in some layers (making them short and wide) and then will catch up in other layers (making them tall and narrow).

What you can do:

• Ensure that your wires are clean and free so that they do not bind or pull.

If you are experiencing the frustration of Z banding, you are not alone. Many individuals are also experiencing the same issue, and there are many causes of this banding. Take the time to troubleshoot your 3D printer using the suggestions here, and soon you will be rid of Z banding for good!