The instructions below are meant to be a guideline for calibrating your extruder. Because every machine is slightly different, it is recommended to also reference your manual during the process. Also, the steps below assume that you have a machine that is running Marlin firmware which is what most consumer 3D printers come with.
Your extruder is responsible for feeding filament through the hotend. It is important that your extruder is accurate with how much material it is feeding to the hotend. If it is extruding too little filament then you will end up with under extrusion which will cause gaps and holes in your print. If your extruder is feeding too much filament, you will get over extrusion which can lead to poor overhand performance and bad print quality overall.
Step 1: Load filament into your extruder and mark a line 110mm from the spot it in enters the extruder. Please note the image below is a metric tape measure. 11cm = 110mm
Step 2: Send M503 to your machine using pronterface (or similar) to get the current E-Step value. You should see M92 followed by a value that starts with E (Be sure to write this number down). Please note your value will likely be different than mine.
Step 3: Send M83 (Relative Mode, nothing should happen)
Step 4: Send M109 S200 (preheats the hotend to 200 degrees C for PLA. If using another filament substitute that temperature here)
**Do not continue until hotend temperature is reached**
Step 5: send G1 E100 F100 (This will feed 100mm of filament through the extruder)
Step 6: Measure the new distance from your reference point to the mark you originally made on the filament. Ideally, this should measure 10mm if your machine is already calibrated. Likely, however, you machine will require some calibration. Calculate the new E-Step value using the formula below:
Dislike Math? Use our free E-Step Calculator:
Step 7: Update the machine with the new E-Steps calculated by sending M92 E(new e-step value)
Example: M92 E426
Step 8: Send M500 (stores new values in EEPROM)
Step 9: You can repeat this process over again to verify your results. Ideally, your measurement should be 10mm after extruding. If you find your measurements are inconsistent, your extruder may be slipping and adjustment might be necessary.
After completing these steps you can be confident that your printer's extruder is accurately calibrated. This will improve the quality of your prints and also make features more accurate with better layer strength.