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6 Ways To Fix Wall Separation in 3D Printing

For the most part, wall separation in 3D printing results from under-extrusion, but there can be other causes. So if you are experiencing gaps between the walls of your 3D prints, you’ll need to adjust or test several different printer settings to remedy the problem. What are these adjustments and settings?

Here are 6 ways to fix wall separation in 3D printing: 

  1. Check for gaps in your model’s design. 
  2. Slow down your print speed.
  3. Adjust your extrusion width. 
  4. Raise the print temperature.
  5. Calibrate your extruder.
  6. Adjust your infill pattern and percentage.

Let’s find a solution and fix your separated walls together. I’ll discuss the settings that might be causing your walls to have hollow gaps in them and teach you how to troubleshoot and adjust them for a more solid print. So, let’s shore up your print’s walls!

1. Check for Gaps in Your Model’s Design

Before we dive into the more technical extrusion-related causes of wall separation, give your 3D model another look-over in your slicer. 

Look through the layers to see if the gaps in your 3D print exist in your design. If you find the gaps, the fix is easy! Just fill in the holes using your CAD program and reprint your model. 

2. Slow Down Your Print Speed

When you print an object too quickly, layer adhesion and thickness suffer. The print speed goes hand-in-hand with the other fixes I’m about to go through, but know that all of the adjustments you need to make to ensure that you get solid walls will slow down the printing process. 

Slowing your print speed will ensure that the extrusion width is accurate and precise, allowing each shell to bond better with the infill. 

3. Adjust Your Extrusion Width

Extrusion width (also called line width) plays a significant role in how well your printer can accurately create shells or walls with infill. If your shells are too thin or a size that does not work well with your layer height, your printer will likely alter the dimensions of the shells or leave some out, making room for wall separation.

When you set an extrusion width and shell width, you also need to think about your layer height and nozzle diameter.  

If you have a standard 0.4mm nozzle, you’ll see the best results when you set your extrusion width somewhere between 0.2mm and 0.8mm. However, you’ll need to match this extrusion width to your layer height because if these two dimensions are not compatible, you will likely experience weak walls or wall separation. 

The Width over Height ratio is a simple number that you can use to match your layer height with your extrusion width. For the best result, the width over height ratio should be at least 1.5 and 2.0. 

So, to find the ideal extrusion width, you will multiply your layer height by some value between 1.5 and 2.0. The result will give you the minimum extrusion width for your print. Aiming for a larger extrusion width will usually only increase your chances of success. 

Let’s look at some examples of how to match your layer height and extrusion width using a 0.4mm nozzle:

  • If you want your layer height to be 0.2mm, your extrusion width should be at least 0.3mm. Generally, since 0.4 mm nozzles have issues when printing layer heights smaller than 0.2 mm, the extrusion width of 0.3mm is the smallest you should ever go with this nozzle. 
  • If you want your layer height to be 0.3 mm, your extrusion width should be at least 0.45mm. 
  • If you want your layer height to be 0.4 mm, your extrusion width should be at least 0.6mm. 

You can use this simple math to find the minimum layer dimensions of any 3D print. 

Still, it’s worth mentioning that most slicers will do this math for you if you enter a height-width percentage. Otherwise, the slicer may approximate the height and width based on your print’s size. But if your dimensions are too small for your nozzle, you’ll start to see layer separation. 

So, in summary, when using a 0.4 mm nozzle, you will likely see layer separation if you attempt to print your walls at an extrusion width of less than 0.3 mm. Try to match your layer height to your extrusion width for more durable prints that bond well with other shells and your infill. 

4. Raise the Print Temperature

If your print temperature isn’t cutting it, your filament won’t be able to extrude correctly, resulting in weaker layers and separating walls. 

So take a second glance at your print temperature before giving your separated print another go. You may need to print the model at a slightly hotter temperature than you would typically use with your filament to ensure that each layer stays hot enough to bond with the outer shells. 

5. Calibrate Your Extruder

Both under-extrusion and over-extrusion can cause wall separation. When you don’t get enough filament in each layer, the sides of these layers won’t be wide enough to reach the print’s infill or outer shell, creating a gap between each component of your object. 

Likewise, over-extrusion can make your layers lumpy, interfering with the thickness of your outer shell and pulling it away from the rest of your print. 

Calibrating your extruder can help you fine-tune your printer’s extrusion rate and ensure that the presets are working correctly for your machinery and filaments. 

To learn more about why and how to calibrate your extruder, check out this tutorial from Crosslink: 

6. Adjust Your Infill and Infill Percentage

The infill settings will significantly impact how well your walls stick together. You’ll need to include enough dense infill to keep the walls from cracking apart and leaving gaps where there should be a solid surface. 

If you are working with Cura, you can use the infill settings to ensure that everything is solid and connected. To adjust the infill settings and sure up your 3D print’s walls: 

  1. Open the “Expert Settings.” 
  2. Select “Connect Infill Lines,” which will mesh the infill with your print’s walls. 
  3.  Enter your print settings and search for “Walls.” 
  4. You should see a line that says “Fill Gaps Between Walls” with a drop-down selection tool. Use this drop-down menu to select “Everywhere.”

Other programs often have similar features, but the location of each menu might differ slightly. Just be sure to find the infill settings on your software of choice and enable the infill to fill every wall, then mesh the infill to your 3D print. 

Another setting worth checking is your infill percentage. If your percentage is too low, your printer may be having difficulty creating a solid bond between the infill and your print’s walls. I recommend using any setting over 50%, but the higher your percentage, the better your results will be. 

Final Thoughts

Wall separation happens when extrusion issues get in the way of layer and shell adhesion. To fix these problems, you’ll need to ensure that your model’s design is solid and includes the correct infill percentage. Then, check your extrusion width, print temperature, and speed. 

Keep the layers large and flat enough for your printer’s nozzle, and take your time on printing. If you patiently go through these steps and work through your issues, you’ll know how to solve any wall adhesion issues that your 3D printer throws your way!