Is your 3D printer suffering from gaps between lines, weak infill, or poor top surfaces? The culprit might be inaccurate extrusion. When your printer thinks it’s pushing out 100mm of filament but is actually only extruding 95mm, you get a classic case of under-extrusion. The fix is surprisingly simple: you need to calibrate your extruder’s E-steps.
E-steps (or extruder steps-per-millimeter) are a critical value in your printer’s firmware that tells the extruder motor how many “steps” to turn to push out exactly 1mm of filament. From the factory, this value is often a good estimate, but it can be off due to manufacturing tolerances in the extruder gear, motor, or even the filament itself.
In this guide, we’ll walk you through the entire process, treating the calibration itself as our “project.” The goal isn’t a fancy model, but something even better: a perfectly tuned machine ready for any print you throw at it.
The “Project”: A Perfectly Calibrated Extruder
Our mission is to measure our printer’s current extrusion accuracy and calculate the correct E-step value to ensure what the slicer asks for is exactly what the printer delivers.
Hardware & Tools Used
Unlike a typical print, we don’t need a slicer for this. We need a few basic tools to communicate with the printer and take precise measurements.
- 3D Printer: Creality Ender 3 V2 (This process works on almost any FDM printer, including Prusa, Anycubic, etc.)
- Filament: Any standard 1.75mm PLA. The color doesn’t matter, but a light color can make marks easier to see.
- Digital Calipers: Essential for accurate measurements.
- Permanent Marker: For marking the filament.
- Control Interface: A way to send G-code commands directly to your printer. Popular options include:
- Pronterface (Printrun): A simple, free desktop application.
- OctoPrint: A web interface for your printer, with a built-in terminal.
- Creality Sonic Pad / Klipper: Use the built-in console.
- Bowden Tube Clip Remover (if applicable)
Slicer Settings
No slicer is needed for this calibration! We will be sending commands directly to the printer’s firmware. This is important because we want to isolate the extruder’s performance without any influence from slicer settings like flow rate or print speed.
The Calibration Process: Step-by-Step
Ready to get your hands dirty? Let’s dive in. The process is simple: we’ll tell the printer to extrude a specific amount of filament and then measure how much it actually extruded.
Step 1: Heat Up Your Hotend
First, you need to heat the nozzle to the appropriate printing temperature for your filament. This allows the filament to flow freely, just as it would during a print. For PLA, we’ll set it to 200°C.
You can do this from your printer’s LCD screen or by sending the G-code command:
M109 S200
Step 2: Get Your Current E-Step Value
We need to know the printer’s current setting to use in our calculation later. Send the following G-code command to your printer’s terminal:
M503
This will display a lot of information saved in the printer’s memory (EEPROM). Look for a line that starts with M92. You’ll see values for X, Y, Z, and E. Write down the E value (e.g., E93.00). This is your current E-steps/mm.
Current E-Steps = 93.00
Step 3: Mark the Filament
This is the most critical measurement step.
- If you have a Bowden tube setup, it’s best to disconnect the tube from the extruder end. This prevents any hotend pressure from affecting the measurement.
- Using your printer’s controls, extrude a small amount of filament until it just starts coming out of the extruder.
- Using your digital calipers and marker, measure 120mm of filament from the point where it enters the extruder. Make a sharp, clear mark.
Step 4: Extrude 100mm of Filament
Now, we’ll command the printer to extrude exactly 100mm of filament. It’s important to do this slowly to ensure accuracy. Send the following G-code command:
G92 E0 (This resets the extruder’s position to zero)
G1 E100 F50 (This tells the printer to extrude 100mm of filament at a slow speed of 50mm/minute)
Wait for the command to finish completely.
Step 5: Measure the Remainder
Now, measure the distance from the extruder entry point to the mark you made earlier. In a perfect world, this would be exactly 20mm (120mm - 100mm). It almost never is.
Let’s say your measurement is 25mm. This means your printer only extruded 95mm instead of the 100mm it was asked to (120mm initial - 25mm remaining = 95mm actual extrusion). This is a classic sign of under-extrusion.
If your measurement was 15mm, it means your printer extruded 105mm (over-extrusion).
Actual Amount Extruded = 95mm
Post-Processing: Calculating and Saving Your New E-Steps
This is our “post-processing” step. We’ll use a simple formula to calculate the new, correct E-step value and save it permanently to the printer.
The Formula:
(Amount You Asked For / Amount Actually Extruded) * Current E-Step Value = New E-Step Value
Let’s Plug in Our Numbers:
(100 / 95) * 93.00 = 97.89
Our new, more accurate E-step value is 97.89.
Saving the Value to Your Firmware:
To set this new value, send the M92 command with your new number:
M92 E97.89
This sets the new value for your current session, but it will be lost if you restart the printer. To save it permanently to the printer’s memory, send the M500 command:
M500
Your printer will confirm the settings have been saved. And that’s it! Your extruder is now calibrated. It’s a good idea to run the 100mm extrusion test one more time to confirm your new value results in a remaining measurement of exactly 20mm.
Final Thoughts & The Showcase of Quality
Calibrating your E-steps is one of the highest-impact maintenance tasks you can perform for your 3D printer. It takes just 15 minutes but is the foundation for achieving excellent print quality. Without accurate extrusion, no amount of slicer tweaking can truly fix issues like gaps, weak walls, or poor surface finish.
The “showcase” for this project is the visible difference in print quality. Below is a comparison of two calibration cubes printed on the same machine.
Before E-Step Calibration: Notice the gaps in the top layer and the slight separation between the perimeter lines. This is classic under-extrusion. The print is structurally weaker.
After E-Step Calibration: The top surface is now perfectly smooth and solid. The walls are strong, and the overall print quality is dramatically improved. This is the result of telling the printer to extrude 100mm and it actually extruding 100mm.
Taking the time to calibrate your machine’s fundamental settings is what separates a beginner from an expert maker. Now that your extrusion is dialed in, you have a reliable baseline for all your future prints. Happy printing