Fine-Tuning Your 3D Prints: A Guide to Extrusion Calibration

Achieving high-quality 3D prints often hinges on precise extrusion. If your 3D printer isn’t extruding the correct amount of filament, you might encounter issues like weak prints, gaps in layers, or rough surfaces. This guide will walk you through a simple yet effective extrusion calibration process, ensuring your “Printed Skirt” – or any 3D printed object – comes out exactly as intended. Even if your current prints appear satisfactory, a quick calibration check can confirm optimal settings and prevent potential problems down the line.

Understanding Extrusion Calibration

Extrusion calibration is essentially about verifying that your 3D printer is pushing out the amount of filament it thinks it is. Over-extrusion means too much filament is dispensed, potentially leading to blobs and dimensional inaccuracies. Under-extrusion, conversely, means too little filament, which can result in weak parts and visible gaps. Whether you’re printing functional components or decorative items like a complex “printed skirt” design, accurate extrusion is crucial for the final product’s integrity and appearance.

Step-by-Step Extrusion Calibration

Follow these steps to calibrate your 3D printer’s extrusion:

1. Preparation: Begin by heating up your 3D printer to your standard printing temperature and load your usual filament. You’ll also need a marker and access to your printer’s G-code terminal (via software like Pronterface or Octoprint).

2. Mark and Measure: Measure 150mm of filament above the point where it enters the extruder and make a clear mark at this point with your marker.

3. Reset Extruder: Open your G-code terminal and use the command G92 E0 to reset the extruder position. This sets the current extruder position to zero, providing a baseline for our test.

4. Extrude Filament: Send the command G1 E100 F30 to extrude 100mm of filament at a feed rate of 30mm/minute. Allow a minute or two for the extrusion process to complete fully.

5. Measure Extruded Length: After extrusion, measure the remaining distance between the top of the extruder and the mark you made on the filament. Subtract this measurement from your initial 150mm mark (150mm – measured value) to determine the actual amount of filament extruded.

6. Evaluate and Adjust:

   • Perfect Calibration: If your measurement is close to 100mm, your extrusion is likely well-calibrated.
   • Over or Under Extrusion: If the extruded length deviates significantly from 100mm, adjustment is needed. For example, if you measured 95mm extruded, you are under-extruding; if you measured 105mm, you are over-extruding.

7. Apply Correction: There are two main ways to adjust your extrusion:

   • Extrusion Multiplier (Slicer Settings): This is often the easiest method for minor adjustments. If you are under-extruding, increase the extrusion multiplier in your slicing software’s filament settings. If over-extruding, decrease it.
   • E-steps (Printer Firmware): For more significant corrections, you can adjust the extruder steps per mm (E-steps) in your printer’s firmware.

8. Calculate New E-step Value (If Adjusting Firmware):

   • First, retrieve your current E-step value by sending the command M503 to your printer. Look for the line starting with M92 and note the ‘E’ value (e.g., M92 E130.00).
   • Calculate the new E-step value using the formula: New E-step value = Current E-step value * (100 / Measured extruded filament in mm). For example, if your current E-step is 130 and you measured 95mm of extruded filament, the new value would be approximately 130 * (100 / 95) ≈ 136.84.

9. Update E-steps: Set the new E-step value using the command M92 E[New E-step Value] (e.g., M92 E136.84).

10. Save Settings: Save the new E-step value to your printer’s EEPROM using the command M500. This ensures the setting persists after restarting your printer.

11. Verification: Repeat steps 4-7 to verify your calibration is now accurate.

Conclusion

Regular extrusion calibration is a simple yet powerful step in maintaining the quality of your 3D prints. By ensuring your printer extrudes filament accurately, you’ll minimize printing defects and achieve better results across all your projects, whether you are creating intricate models or practical parts. Even small discrepancies can impact the final outcome, so taking the time to calibrate, especially when starting with a new filament or after printer maintenance, is a worthwhile investment for consistent and reliable 3D printing.