Most 3D printer users have experienced Z banding or ribbing issues at some point in their 3D printing journey, same with me. I wondered though, how do we fix this Z banding issue, and are there simple fixes out there?
The best way to fix Z banding in your 3D printer is to replace your Z-axis rod if it is not straight, enable consistent bed temperature with PID, and use layer heights which avoid your 3D printer using microstepping. A faulty stepper motor might also cause Z banding, so identify the main cause and act accordingly.
These fixes are fairly easy to do but keep on reading for more key information. I’ll give you a detailed description on how to do them, as well as what to look out for and other tips to fix Z banding issues.
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What is Z Banding in 3D Printing?
Many issues in 3D printing are aptly named after what they look like, and banding is no different! Z banding is a phenomenon of bad 3D print quality, which takes on the visual of a series of horizontal bands along a printed object.
It’s pretty easy to figure out whether you have banding just by looking at your print, some being a lot worse than others. When you look at the image below you can clearly see the thick lines with dents which look like actual bands on the print.
In some cases, it can look like a cool effect in some prints, but most of the time we don’t want Z banding in our objects. Not only does it look rigid and imprecise, but it also causes our prints to have a weak structure, among other downsides.
So we can determine that banding is not an ideal thing to be happening, so let’s look into what causes banding in the first place. Knowing the causes will help us determine the best ways to fix it and prevent it happening in the future.
What Causes Z Banding in Your Prints?
When a 3D printer user experiences Z banding, it’s usually down to a few main issues:
- Bad alignment in the Z axis
- Microstepping in stepper motor
- Printer bed temperature fluctuations
- Unstable Z axis rods
The next section will go through each of these issues and try to help with fix the causes with a few solutions.
How Do You Fix Z Banding?
You might have tried several things to fix Z banding, but they just aren’t working. Or you have recently discovered it and searched for a solution. Which ever reason you came here for, this section will hopefully give you the guidance to fix Z banding once and for all.
The best way to fix Z banding is to:
- Correctly align the Z axis
- Use half or full step layer heights
- Enable a consistent bed temperature
- Stabilize Z axis rods
- Stabilize bearings and rails in other axis/print bed
The first thing you should look at is whether the banding is uniform or offsetting.
Depending on the exact cause, there will be different solutions that you should try first.
For example, if the main cause is from a wobble or uneven movement from the rods, your banding will look at certain way.
The banding here would be where each layer slightly shifts in a certain direction. If you have Z banding which mostly comes out on just one side, it means the layer should be offset/depressed on the opposite side.
When the cause of your Z banding is to do with layer heights or temperature, you are more likely to get a banding which is uniform and equal throughout.
In this case, layers are wider in all directions compared to another layer.
Z Axis Alignment Correction
The video above shows a case of a poor Z-carriage bracket that holds the brass nut. If this bracket is badly manufactured, it might not be as square as you need it to be, resulting in Z banding.
Also, the screws of the brass nut shouldn’t be fully tightened.
Printing yourself an Ender 3 Adjustable Z Stepper Mount from Thingiverse can help out a lot. If you have a different printer, you can search around for your specific printer’s stepper mount.
A flexible coupler also works well to get your alignment in order, to hopefully eliminate the Z banding you have been experiencing. If you are after some high quality flexible couplers, you’ll want to go with the YOTINO 5 Pcs Flexible Couplings 5mm to 8mm.
These fit a wide range of 3D printers from Creality CR-10 to Makerbots to Prusa i3s. These are made of aluminum alloy with great craftsmanship and quality to eliminate the stress between your motor and the drive parts.
Use Half or Full Step Layer Heights
If you choose the incorrect layer heights, relative to your 3D printer’s Z axis, it can cause banding.
It is more likely to show up when you are printing with smaller layers since the error is more pronounced and thin layers should result in pretty smooth surfaces.
Having some incorrect microstepping values can make it harder to fix this issue, but luckily there is an easy way to get around this.
When you compare the movement precision of the motors we use, they move in ‘steps’ and rotations. These rotations have specific values of how much they move, so a full step or half step moves a certain number of millimeters.
If we want to move at even smaller and more precise values, the stepper motor has to use microstepping. The downside of microstepping though, is the movements aren’t as precise as we want them to be.
It is easy to avoid your extruder having to use microstepping by using either the full or half-step values for your 3D printer, relating to layer heights.
I did a recent post which has a section about microstepping/layer heights and its ability to give you better quality prints.
Basically, with an Ender 3 Pro 3D printer you have a full step value of 0.04mm. How you use this value is by only printing in layer heights that are divisible by 0.04, so 0.2mm, 0.16mm, 0.12mm and so on. These are known as ‘magic numbers’.
These full step layer height values mean you don’t have to kick into microstepping, which can give you uneven movement throughout the Z axis.
Enable a Consistent Bed Temperature
A fluctuating bed temperature can cause Z banding. Try printing on tape or with adhesives and no heated bed to see if you still experience Z banding on your prints. If this solves the problem, then it’s probably an issue with temperature fluctuations.
The two types of bed heating processes are called Bang-Bang bed heating or PID bed heating. Bang-Bang bed heating is when your 3D printer reaches the set bed temperature and stops heating, which then causes it to cool down.
The bed then hits a certain point below the set bed temperature then kicks in again to hit the set temperature. Bang-Bang, referring to hitting each of those temperatures several times.
This can result in your heated bed expanding and contracting, at a level just high enough to cause print inconsistencies.
PID (Proportional, Integral, Differential terms) is a loop command feature in Marlin firmware to autotune and regulate bed temperatures to a specific range and stops wide temperature fluctuations.
This older video from Tom Sanladerer explains it pretty well.
Turn on PID and tune it up. There can be confusion when using the M303 command when identifying the extruder heater versus the bed heater. PID can keep a good, consistent temperature of your bed throughout a print.
The heating cycles of the bed fully turn on, then cool down before starting back up again to reach your overall set bed temperature. This is also known as bang-bang bed heating, which happens when PID isn’t defined.
In order to solve this, you need to adjust a few lines in Marlin firmware’s configuration.h:
// … Next section down …
The following worked for an Anet A8:
M304 P97.1 I1.41 D800 ; Set the bed PID values
M500 ; Store to EEPROM
This isn’t on by default because some 3D printer designs don’t work well with the rapid switching that occurs. Make sure before doing this that your 3D printer has the capabilities to use PID. It’s automatically on for your hotend heater.
Stabilize Z Axis Rods
If the main shaft isn’t straight, it can cause a wobble which results in bad print quality. Bearing at the top of each threaded rod contributing to banding, so it can be a series of causes that add up to make banding as bad as it is.
Once you identify and fix these causes of banding, you should be able to eliminate this negative quality from affecting your prints.
A bearing check on the Z rods is a good idea. There are rods out there straighter than others, but none of them would be perfectly straight.
When you look at how these rods are set up on your 3D printer, they have the potential to not be straight, which offsets the Z axis slightly.
If your 3D printer is clamped in bearings, it can be off-center since the hole where the rod fits through isn’t the perfect size, allowing for extra unnecessary movement side to side.
These side to side movements cause your layers to be misaligned which results in the Z banding that you are familiar with.
Caused by a poor alignment of the plastic bushings on the extruder carriage. This increases the presence of vibrations and uneven movements throughout the printing process.
For such a cause, you would want to replace the ineffective rails and linear bearings with hardened rails and high quality bearings. You might even want a metal extruder carriage if you have a plastic one.
If you have two threaded rods, try slightly rotating one of the rods by hand and see if they are both synced up.
If the Z nut is higher up on one side, try to slightly loosen each of the 4 screws. So basically trying to get an equal angle on each side, so the movements aren’t unbalanced.
Stabilize Bearings & Rails in Other Axis/Print Bed
The bearings and rails in the Y axis can also contribute to Z banding so definitely check over these parts.
It’s a good idea to do a wiggle test. Grab your printer’s hotend and try wiggling it to see how much movement/give there is.
Most things will move a little bit, but you are directly looking for a large amount of looseness in the parts.
Also try the same test on your print bed and fix any looseness by shimming your bearings into better alignment.
For example, for the Lulzbot Taz 4/5 3D printer, this Anti Wobble Z Nut Mount aims to eliminate minor Z banding or wobble.
It doesn’t require a firmware update or anything, just a 3D printed part and a set of materials that attach to it (described on the Thingiverse page).
Depending on the design of your 3D printer, you might be more likely to experience Z banding. When the Z axis is secured with smooth rods, along with threaded rods which have bearings on one end that move it up and down, you won’t have this problem.
Many 3D printers will use the combination of a threaded rod connected to your Z stepper motor shafts to hold it in place through its internal fitting. If you have a printer with a platform carried by the Z axis, you can experience banding through wobble of the platform.
Other Solutions to Try Fix Z Banding in 3D Prints
- Try putting some corrugated cardboard underneath your heated bed
- Put the clips that hold your bed in place right at the edge
- Ensure that aren’t any drafts that affect your 3D printer
- Screw up any loose bolt and screws in your 3D printer
- Make sure your wheels can move freely enough
- Decouple your threaded rods from smooth rods
- Try a different brand of filament
- Try increasing the minimum time for a layer for cooling issues
- Grease your 3D printer for smoother movements
There are many solutions to try out, which is common in 3D printing but hopefully one of the main solutions works for you. If not, run down a list of checks and solutions to see if one of them works out for you!
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I hope this article helps you out. Happy Printing!