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7 Common Cura Problems and Fixes

Ultimaker Cura is one of the most popular 3D printing software available on the market today. Notably, it’s a fantastic program to use for slicing 3D prints. Still, despite the program being one of the best slicers in demand, users occasionally run into a few problems. 

Here are 7 common Ultimaker Cura problems: 

  1. Cura Model Errors 
  2. Manifold Error 
  3. Overhang 
  4. Zits and Blobs
  5. Cura Not Slicing 
  6. Cura Not Detecting USB Printer 
  7. Cura Not Generating Supports 

While these aren’t the only Cura problems, they’re the most common and most troublesome. 3D software can be complicated, but you can easily and quickly get back to printing with a bit of know-how. Please keep reading to learn the common problems that occur with Cura and the best ways to fix them. 

1. Cura Model Errors

One of the most common problems that Cura users run into is model errors. A few reasons for this may include: 

  • Self-intersecting 
  • Separate objects 
  • Holes 
  • Inner faces  

Self-intersecting is basically when your mesh has clipping, and it tends to happen with more complex models. 

Cura doesn’t recognize the model in your software due to original design model errors. That can be frustrating when trying to print your model. It can be even more frustrating than getting a leaking nozzle because at least your model prints. 

Inner faces happen when there’s a model within a model. If the mesh has problems in your chosen 3D modeling program, it should be fixed before printing. Luckily, there’s an easy fix to get your model up and working again. 

How To Fix

model error occurs when the model has an error in the mesh. The error is already causing problems before exportation, so the mesh problem must be located and fixed before you can print out your model using Cura. 

Fix the model error using these steps: 

  1. Go into your 3D Design Software settings
  2. Look for any models errors and export them into Cura
  3. Locate the problem and alter the design in your chosen 3D design software (such as Blender or Maya) 
  4. Reload back to Ultimaker Cura by exporting another 3D model from your software 
  5. Manifold Error

2. Manifold Error

Another common problem you may run into while attempting to slice your model is a manifold geometry error. 

3D Models must have a manifold. Manifold is simply a way of saying that what supports a 3D model in a virtual sense does not support a model in the real world. If your model has a non-manifold mesh, it won’t print correctly in the real world. 

Non-Manifold is when more than two faces share any model edge; Essentially, two identical edges are on top of each other. This can happen when the model’s edge is extruded but not moved. 

Making your mesh watertight is essential when slicing. Cura won’t print if it recognizes your mesh having holes; it fails to read the file properly and displays an error message. Holes will cause problems when trying to print. It may seem silly, but Cura must ensure the mesh doesn’t have any openings before it marks the print as acceptable enough to slice. 

How To Fix

A 3D model mesh is manifold, which means it has holes within the shell. An object with a non-manifold will cause Cura to slice the model incorrectly. 

To fix this, click on the “file” tab in the drop-down menu and locate the “Repair STL file” button. This method isn’t always successful for every model, but it’s worth a shot before attempting a more complex fix. 

If this method fails, try redesigning your mesh with your chosen 3D modeling software.

3. Overhang

You may come across a problem in your model called the overhang. The overhang angle is how much support material your model has. A slight angle leads to more support. This problem occurs when Cura thinks a vertical wall is present when it’s not. This usually is due to the mesh having the wrong normals. 

Any 3D model with more than 45 degrees horizontal edges is challenging to print. The material must be stable, and overhangs will cause curling, delamination, sagging, or even collapse during the printing process.

How To Fix

There are a couple of easy fixes you can try to fix your model from having an overhang:

  1. Check your settings in the section “mesh fixes.” If your model is acceptable, then Cura can fill the parts that need extra filling without you having to redesign. 
  2. Click the gear and locate the fixes and make them all visible. If your “union overlapping volumes” are causing the overhang problem, this box must be unchecked. 

Keep in mind that settings save. If you fix things to make all of the faces visible, it may be necessary to readjust for future prints. 

4. Zits and Blobs

Throughout the printing process, the extruder usually maintains a steady extrusion. However, switching between on and off may cause problems. Notably, once a layer is finished printing, a quick blast of over-extrusion can occur if the print head’s filament remains pressurized. Such markings can also be seen at the extruder’s starting point. These are known as zits and blobs.

Here are some common reasons for zits and blobs to occur:

  • Printing temperature is high
  • Extruder pathing is incorrect
  • Coasting is unsuitable
  • Printhead is stuttering
  • The extrusion system has built-up pressure 
  • Too much filament 
  • The mainboard is too slow

How To Fix

Here are the common solutions for avoiding zits and blobs:

  • Retract and wipe all settings
  • Verify the restart distance 
  • Relocate the starting point 
  • Lower the speed of printing
  • Adjust the coasting 
  • Reduce extrusion multiplier 
  • Lower the print temperature 
  • Adjust Maximum Deviation and Resolution

5. Cura Not Slicing

Cura sometimes fails to slice when required. There are many reasons why this may happen; however, it can sometimes occur for no apparent reason. You may click “Prepare,” but nothing happens after this. 

Cura can also sometimes stay stuck on the “Slicing” option without anything ever moving or happening. That can be a frustrating problem among Cura users. Cura is not perfect and is constantly being updated. It’s also a free program and only accepts donations, so updates are sometimes far and few in-between. You may need to fiddle with adjustments to get your Cura to work. 

How To Fix

That can be a frustrating problem and happens randomly. You may have to try a few different solutions that can be time-consuming. Here are a few methods to fix a Cura not slicing issue: 

  • Uninstall and reinstall Cura 
  • Reset your settings to default 
  • Shut off a firewall if necessary 

If none of these troubleshooting techniques work, Cura has a setting under quality called the “cutoff object bottom” in the advanced tab. Try setting this to a non-zero value. 

If problems persist, force the settings into factory setting mode by following these steps:

  1. Go to the “Help” tab
  2. Find the “Show Configuration Folder” (This opens the folder that holds your settings for Cura) 
  3. Close Cura and then remove everything from that folder
  4. Restart the program to put the settings back to factory default

6. Cura Not Detecting USB Printer

A common issue with Cura Ultimate is Cura doesn’t detect your USB printer. This happens pretty often, and Cura users find it a frustrating problem among a few others. 

You may decide that connecting a USB port to your computer and printing via USB is a great idea; however, users may experience problems with connectivity. 

Here’s a great video that explains this issue further:

To get your USB printer detected without using a third-party program, use an SD card or Bluetooth connection, whichever is best for you. 

How To Fix

A few easy ways to fix Cura not detecting a USB printer are: 

  • Check the port and baud rate in the device manager. Verify that this matches your machine settings in Cura, as this certainly causes your USB not to be detected. 
  • Check the USB cord itself. If you have tried the following methods with no luck, then replacing the cord may be the best bet. Many users who have trouble with USB ports usually have a faulty cable or port. You may try to replace the line before adjusting the settings within Cura itself.
  • Use your SD card rather than a USB port. That can be a more straightforward fix than using a USB. Make sure your drivers are all up to date, as expired drivers can sometimes cause connection issues. 

7. Cura Not Generating Support

If you need support on your overhang, the settings are marked as “Support Overhang Value,” and Cura still isn’t printing or showing support for your overhang, then your overhang may be too small for Cura to recognize.

If you are running Cura on Windows 10 or Windows 7, you may also experience problems. Cura software sometimes won’t open or opens incorrectly if your computer runs on outdated software. Remember to update your drivers and your computer before using Cura. 

How To Fix

To fix the overhang, try changing your value to zero. This should force Cura to recognize your overhang, no matter how small. You may also load your model into a meshmixer to use their tree support, or you may add your own to your model in places you desire. 

You may also need to check your settings. For instance, settings may be on “everywhere” and not “touching build plate.” Or it may be necessary to adjust the support distance setting until support shows up on the model. 

Before redesigning your model or adjusting any settings, verify that you’re using the most updated version of Cura. Many users have reported this problem when using an older version. 

The Best Cura Settings

If you have problems with Cura, you may need to adjust some of your settings. The wrong settings can cause significant problems when 3D printing and modeling. Always check to ensure the appropriate settings are locked in before troubleshooting problems more in-depth. 

Here are some appropriate basic settings for your Cura software: 

  • Layer Height Should be at 0.12 mm (0.005 in) 
  • Infill Should be at 20% 
  • Initial Fan Speed should be at 0 
  • The speed of the first layer should be 20 mm/s (0.8 in/s) 
  • Retraction should be at 6mm (0.24 in) 
  • The print temperature should be at 200°C (392°F) 
  • Printing bed temperature should be at 50°C (122°F) 

Keep in mind that settings also depend on what type of material is used to create the 3D models. Different filaments melt at different temperatures. However, these basic settings ensure your Cura settings are similar settings for your 3D printer. 

It’s important to remember that bed and melt temperature is essential to printing the best 3D models. If you are using a material that melts too fast, you may experience many problems such as nozzle leaking or other issues. 

Having the correct settings for your 3D printer and Cura is crucial for having the best-looking models. Remember that no model is ever perfect, and some imperfections are inevitable, but having the correct settings for your printer is vital to having great prints. 

3D printing is a complex hobby; it requires a lot of learning and understanding of complex programs such as Maya or Blender or other programs that design 3D prints. You may have to take the time to read through many manuals to troubleshoot your problems. It’s not an easy process, and it may be pretty time-consuming. You may also need to replace, redesign, or remake many of your models before being able to slice and print correctly. 

It’s essential to take the time needed to learn about these different types of programs before diving into 3D printing. You may damage or break pieces of your printer that have delicate parts. Be sure to have your settings placed correctly before upgrading or replacing any parts inside your 3D printer. 

Cura is a fantastic program, but with any program, there are bugs. If you have a problem that you don’t believe can be fixed with any of the above solutions, then you may need to report these bugs to the Cura developers. Many bugs are issues with the software itself and will be fixed with the next big update.