This post is part of the Calibration series.

When doing something on a 3d printer, most of the times you don’t need to do anything, but sometimes it is neccesary to calibrate some stuff. Changing the hotend, heatbed will force you into doing that.

Extruder calibration

If you have a bowden setup, decouple the bowdeb tube from the extruder

M503 ; report the old M92 value

Say the old value is 400

M83 ; set extruder in relative mode
M302 ; report minimum extrusion temp (170)
M302 P1 ; enable cold extrusion

Place a dot mark on the filament some 12 cm an measure the start of the dot to the begin of the extruder, say 12.5 cm.

G1 E100 F100 ; extrude 10 cm of filament

Again measure the distance from the dot to the begin of the extruder, say 2.9 cm, and calculate the difference: 12.5 2.9 = 9.4 The new M92 value should be:

400*10/9.4 = 425.53

Setting the new M92

M92 e425.53

And storing and reviewing it with:

M500 ; Save settings to eeprom
M501 ; Set Active Parameters
M503 ; display current settings

Nozzle and bed temperature PID calibration

Nozzle PID calibration 8 times at 225°C:

M303 E0 S225 C8 ; extruder 0 at 225oC 8 times

This will at the end give the P, I and D values, store these with:

M301 P12.53 I0.71 D55.59

For the bed use bed use the next command:

M303 E-1 S60 C5 ; bed at 60oC 5 times

And store it with

.. code-block::

M304 P10.97 I1.01 D79.53

As a last step:

M500 ; Save settings to eeprom
M501 ; Set Active Parameters
M503 ; display current settings

And you are done.

Bed calibration with bl-touch

After changing the something to the bed it is necessary to change the M851 Z height. This is done in 15 simple steps:

G28 ; Home the printer
M851 Z0 ; Reset the Z offset
M500 ; Store active parameters
M501 ; Set active parameters
M503 ; Display active parameters
G28 Z ; Home Z axis
G1 F60 Z0 ; Move nozzle to the true 0 offset
M211 S0 ; Switch of soft end stops

Move bed slowly using a feeler gauge for example .2 mm, using the printer z-menu Take a note of the Z on the printer display and add feeler gauge size in this case .2 mm

M851 Z-2.80 ; the -2.8 is the achived z-offset, -2.6 on the printer and .2 from the feeler gauge
M211 S1 ; re-enable the soft end stops
M500 ; Store active parameters
M501 ; Set active parameters
M503 ; Display active parameters

And you are done.