5.2 Dual Extruder Calibration
If your printer has only a single extruder, or if you never use two
extruders for the same print, then you can skip this section.
When printing with both extruders, optimal print quality is
achieved by precisely calibrating the distance between the two
extruder nozzles. As explained in Section 4.2, this calibration
information is stored as the “toolhead offsets”. In this section, a
method of determining the toolhead offsets is presented. For every
major type of printer, there is a nozzle calibration print in
“ReplicatorG 40 – Sailfish”, that may be printed as described and
then the results supplied to your printer. Using the results of your
print, your printer will then set the correct values for the toolhead
- Before you begin, ensure that you have the latest Replicator
G 40 – Sailfish downloaded from the Sailfish “Thing” at
- Launch ReplicatorG and select the correct machine type
under the “Machine Type” item of the “Machine” menu. Be
sure that the machine type name includes “(Sailfish)” in it.
Figure 5.5 shows The Replicator Dual (Sailfish) selected.
Figure 5.5: Machine Type
- Connect to your printer over USB (see Figure 5.6), then invoke
the Onboard Parameters window with the “Onboard
Parameters” item of the “Machine” menu.
Figure 5.6: Connecting to Your Printer
- In the “Homing/VREFs” tab, set the X and Y toolhead offsets
to 0.0 mm. Be sure to change the toolhead offsets and not the
home offsets (Figure 5.7). Make sure to commit the change.
Note that resetting the printer to factory defaults will not reset
the X and Y toolhead offsets.
Figure 5.7: Toolhead Offsets
- To print the nozzle calibration print go to the “Scripts” item of
the “File” menu, choose your printer type, and then select the
“Dual Nozzle Calibration.gcode” item (Figure 5.8). Select the
Replicator 1 if you do not see your printer type listed. Note
that the name may be an elongated version of this such as
“Flashforge Creator Dual Nozzle Calibration.gcode”.
Regardless, selecting this will bring up the gcode file in
ReplicatorG which you should then print to your printer.
Figure 5.8: Nozzle Calibration Menu
- Once the print is finished, you will see a series of horizontal line
pairs running vertically up the left side of the build plate
(Figure 5.9). Each pair of lines was printed using both
extruders, and is numbered with a value between 1 to 13. Line
1 is at the front of the plate and should be the longest.
Identify the pair for which each line is vertically the best
aligned. Remember this number. In the example print
of Figure 5.9, either lines 1 or 2 seem to have the best
Figure 5.9: Nozzle Calibration Print
- The print will also have a series of vertical line pairs running
horizontally across the front of the build plate. Again, each pair
of lines was printed with both extruders, and are numbered 1 to
13. Line 1 is the leftmost and should also be the longest.
Identify which pair has the best alignment — which pair has
the middle ends closest horizontally. Remember this number.
In the example print of Figure 5.9, pair 6 appears best
- On the printer’s LCD screen navigate to the “Calibrate
Nozzles” item under the “Utilities” menu (Section 3.7.18). For
the X and Y values, input the numbers you recorded for steps 7
and 6, respectively. Then select the “Done” item on the fourth
line of the screen.
- Your toolhead offsets have now been set. The values in
ReplicatorG’s Onboard Preferences will have changed unless
you entered 7 for both X and Y, as Line 7 represents the ideal
offset of 0.0 mm. The actual lines are offset by by -0.6 mm,
-0.5 mm, ..., 0.0 mm, 0.1 mm, ..., 0.6 mm, creating thirteen
Note, however, that, should you revisit the Calibrate Nozzles
item on your printer, you will not see the X and Y values you
entered, as the printer does not save these values but instead uses
them to recalibrate. It is worth mentioning that, after recalibration,
these values are no longer correct: if you were to reprint the nozzle
calibration print, you should now find that Line 7 is the best match
for both X and Y.