Blobs & ZitsUpdated 3 months ago

Blobs and zits are common imperfections that can detract from the quality of your prints. They typically appear at points where the extruder starts or stops depositing material. Understanding what these imperfections are and how to address them is crucial for enhancing the quality of your prints. This article will explain the causes behind blobs and zits and provide practical solutions to mitigate these issues.

What Are Blobs and Zits?

Blobs

Blobs are surplus amounts of filament that are deposited at the beginning of a new segment of printing. When the extruder starts to move after a brief pause, it may release a small amount of excess plastic, creating an unwanted bump or glob on the surface of the print.

Zits

Zits, on the other hand, are similar deformities that occur at the end of a segment, generally when the extruder stops. As the nozzle halts, pressure built up inside the nozzle can force out a tiny amount of filament, leaving a small dot or imperfection at the point of cessation.

Both blobs and zits can impact the aesthetics and functionality of a 3D print, but fortunately, there are several strategies you can employ to minimize or eliminate them.

Solutions for Blobs and Zits

1. Optimize Retraction Settings

Retraction is the process of pulling filament back into the nozzle to prevent oozing when the extruder is not actively printing. Adjusting your retraction settings can significantly reduce the occurrence of blobs and zits.

• Increase Retraction Distance: Experiment with the distance that the filament is pulled back during retraction; longer distances can help mitigate oozing.
• Adjust Retraction Speed: Slower retraction speeds can prevent filament from snapping or stretching excessively, leading to better control.

2. Fine-Tune Temperature Settings

Extruder temperature can influence the flow of filament:

• Lower the Nozzle Temperature: Excessively high temperatures can lead to more ooze. Try lowering the temperature incrementally and observe how it affects your prints.

3. Use a Z-Hop Feature (if available)

Z-hop is a movement feature in many slicing software programs that lifts the nozzle slightly during non-print moves. This can minimize dragging across previously printed areas and reduce the chances of producing blobs and zits.

• Enable Z-Hop: Check your slicing software settings to enable this feature, adjusting the height based on your specific needs.

4. Optimize Print Speed

• Reduce Print Speed: Slower print speeds allow for better control of filament flow. While this may slightly increase print times, it can lead to a cleaner finish.

5. Adjust Travel Movements

• Minimize Travel Distance: If the print head has to travel long distances without printing, it can lead to more ooze and therefore more blobs and zits. Design your model or adjust settings to reduce unnecessary travel.
• Use "Combing Mode": This feature can keep the print head within the already printed areas to reduce oozing on the travel.

6. Clean the Nozzle Regularly

A clogged or dirty nozzle can lead to inconsistent flow of filament:

• Routine Maintenance: Regularly clean the nozzle to ensure good quality printing. This keeps the filament flowing smoothly and can reduce the chance of blobs and zits.