Calibrate Extruder

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We'll extrude 100mm of filament and measure what actually extruded:

• Connect USB cable from a computer to the Ultimaker Original+
• Connect Printrun / Pronterface to the printer: Baud rate: 250000. Any software that allows you to send single-line G-code commands to the printer will do. Examples include Simplify 3D, Pronterface, Repetier Host, and OctoPrint.
• Heat up your hotend to your regular printing temperature and ensure that the nozzle is in a position above the bed where it can freely extrude filament.
• change the filament to white. (to make the marks easily visible)
• In printrun set the extrusion length to 100mm and the speed to 50mm/min (needs to be slow!)
• with calipers, measure 120mm(!) from the underside of the feeder. It's possible to scribe the distance directly into the pastic with the calipers, but using a ballpoint mark is also possible
• Send the command M83. This will ensure that your printer is interpreting the following extrusion commands in relative mode.
• extrude 100mm(!) at 50mm/min
  • G1 F50
  • G1 E100
• cool down hot end
• measure from the underside of the feeder to the mark made previously.

If it measures 20mm you're good and you can skip the next steps. If not, keep reading.

• Get the existing E-steps/mm value
  • send M503
  • look for the line “echo: M92 X78.74 Y78.74 Z200.00 E868”
  • look for the E-value in the line. In this case: 868
• 120 - measurement = actual extrusion distance
  • in this case: 120 - 21mm = 99. (We're 1mm off)
• Desired extruded distance / actual extruded distance = correction multiplier:
  • 100 / 99 = 1.0101010101
• Correction multiplier × original extruder steps/mm = calibrated extruder steps/mm:
  • 1.0101010101 × 868 = 876,7676
• Send new value to the printer:
  • M92 E876.7
• Save setting in memory
  • M500
• Test if it was saved:
  • M503
• Look for the line “echo: M92 X78.74 Y78.74 Z200.00 E876.70” and check the E-value.

Do another extrusion test. Keep repeating these steps until the measurement after extruding is exactly 20mm.

• measure the diameter of the filament at a few points with a micrometer and take the average
  • for example: 2,89, 2,86, 2,88 averages out to 2,8767
• enter this value as the filament diameter in the slicing application
• in the slicing application, set the extrusion multiplier to 1 (in Cura: flow 100%)
• Check the slicer value for “line width” and remember for later
  • in this case: 0,4mm
• load a cube and slice it in vase mode at 0,15mm
• print and measure the thickness of each wall and take the average.

If the measured thickness is the same as the set line width, good! You're done! If it isn't keep on reading.

• Calculate new extrusion multiplier (or Flow) value
  • if the flow parameter is in percentage, divide by 100: for example: 100% flow is extrusion multiplier of 1.0
  • (current extrusion multiplier × extrusion width in mm) / measured wall thickness in mm = new extrusion multiplier
  • in my case: (1 x 0,4) / 0.4375mm = 0,9142 (or flow rate would be: 91,42%
  • Enter the new extrusion multiplier into your slicer and print the model again and re measure the wall thickness. It should only take one adjustment, but it may take a few tries to get it right.
  • This extrusion multiplier value should be calibrated and set on a per material basis due to the different flow characteristics of different materials when extruded (eg. viscosity, die swell). It may also vary between different brands of the same material type too, so keep this in mind.

After you have completed all these steps, it’s a good idea to tune or re-tune your first layer height, which may need adjustment