Extruder Calibration

Extruder (e-steps) calibration makes your printer push out exactly the length of filament it's told to — the foundation every other calibration depends on. You command 100mm of extrusion, measure what actually fed through, and adjust the steps-per-millimetre value if it's off. Do this first, before temperature, flow, or retraction.

The purpose of this calibration is to ensure correct material deposition during 3D printing. If the extruder pushes too little material, the object will have gaps or weak, thin walls (under-extrusion). If it pushes too much, you get over-extrusion — blobs, rough surfaces and stringing.

Materials and tools required

To perform this operation you will need:

• Your usual slicer
• A rigid filament
• Calliper or ruler (measuring tool)
• A permanent marker

Procedure

Step 1

The first thing to do is to load the filament into the printer as usual. If you already have rigid material loaded in your machine just preheat the extruder.

Step 2

Connect your printer to your computer via USB or WiFi to be able to send G-code commands. If your slicer does not allow this option, download and install Pronterface to do this operation.

Step 3

With the help of the gauge and the marker pen, measure and mark the filament 110mm from the extruder inlet. Then send the following command from the computer: G1 E100 F100
This command orders 100mm of material to be extruded at a conservative speed to avoid any interference caused by filament tension or pressure on the hotend.

Step 4

Measure from the mark to the extruder inlet area and write down the value given. If this value is 10mm, the extruder is well calibrated. But if it is different, we must recalculate the steps per millimetre of the extruder.

To obtain the current number of steps per millimetre, send the command M503 and the printer will return a series of values. Among all these, you have to locate where it says M92 and then the number that accompanies E-value (normally at the end of this line). This number is the steps per millimetre.

Step 5

To calculate the new value of steps per millimetre, we have to find out how much material has actually been extruded. To do this, we subtract the measurement, we made with the calliper from 110mm.
Using the following formula we will get the exact value for the extruder pitches per millimetre:

Step 6

All that remains to be done now is to enter this new value in our printer. To do so, send the following command: "M92 value" (replacing value by the value obtained). Next, send the M500 command to store this value in the memory of our printer.

To check that everything has been saved correctly, turn off the printer and check again with the "M503" command to see if the new steps per millimetre have been saved correctly.

Step 7

Go back to step 3 and perform this calibration again to check that it has been done properly.

Frequently Asked Questions

What are e-steps (steps per millimetre)?

E-steps are the number of stepper-motor steps your printer's firmware uses to push 1mm of filament through the extruder. If this value is wrong, every print will be slightly under- or over-extruded, no matter what other settings you tune — which is why extruder calibration comes first.

Why command 100mm but mark at 110mm?

You mark at 110mm so the reference point stays outside the extruder body after 100mm feeds in. After extruding, the distance left between the mark and the inlet should be exactly 10mm if calibration is perfect; the difference from 10mm tells you how far off your e-steps are.

How do I save the new e-steps permanently?

Send M92 E followed by your calculated value to set it, then M500 to write it to the printer's memory. Power-cycle the printer and run M503 to confirm the new value was stored before reprinting the test.

What should I calibrate after the extruder?

With e-steps correct, move on to the temperature tower, then the flow test, and finally the retraction test. Each one assumes the extruder is already accurate.

---

About the author
Sergio Peciña is a qualified Electrical & Electronics Engineer and Eolas Prints' Technical Design Engineer, with over 10 years of experience in 3D printing. He founded the maker spaces at the University of La Rioja and IDIVAL Santander. Every Eolas Prints filament is manufactured in-house in Cantabria, Spain, to ISO 9001 and ISO 14001 standards.

Accurate calibration starts with consistent, tight-tolerance filament: shop PLA | PETG — ±0.05 mm tolerance, made in Spain. See more calibration guides in our troubleshooting & calibration hub.