Dual extruder e step calibration - g-code to switch work nozzle

Snapmaker 2.0
1

Hello, I am following guides to calibrate e-steps, but I am not sure how to do this for a dual extruder. I understand that calibration will apply to both hot ends. I am failing to verify the second nozzle. When I use T0 current work nozzle is selected, T1 does not help me. How do I switch Current Work Nozzle through Console or Luban?

Thanks.

2

G91; relative movement

G1 T0 E100.00 F50
or
G1 T1 E100.00 F50 worked for me testing.

M92 T0 EXXX.XX
M92 T1 EXXX.XX
to store / set
G92 ; absolute movement
M500 to save

all found on the famous
https://teachingtechyt.github.io/calibration.html#esteps

but the two shouldn’t need two different numbers. They could just saying they shouldn’t.
By default it copies the T0 value to both.

Remember e-steps program the mechanical items only, even with different dia nozzles.
flow % and slicer settings set the material differences. so XYZ and E-steps are independent of material.

3 Likes
3

Thank you, this was helpful.

I also forgot to put extruder in a relative movement mode so I pushed fillament out of the extruder enough for it not to engage, but not enough to be obvious from outside. After I figured that out it all started to work.

4

oops i will add that incase others read it


1 Like
5

Its M83 for relative extrusion but i guess it would work with relative movement too.

6

Yes from g-code’s point of view the extruder is just another axis

7

the code i came up with based on the measurements I got (there does not seem to be a T0 T1 in anything I have read).

“M92 Current E702.21, BACKUP SINGLE E223.28, BACKUP DUAL E702.21”(that is the statement I used exactly)

the Current E702.21 is SINGLE E223.28 * Pi~ (not exactly Pi but really close). I got that value based on the values from the original M503 inquiry:
M92 X400.00 Y400.00 Z400.00 B888.89Current E667.22, BACKUP SINGLE E212.21, BACKUP DUAL E667.22
it will verify the corrected values but it will not run G1 E100 F50. Tested my findings using @Spaced Block from another thread. it takes 0.1 m of 1.75mm PLA. It checks nearly perfect for me.

There is a setting in Luban to set your flow rate %. if you do not want to risk screwing with recoding your machine. You could run your filament of choice and calculate the % you are off and correct it in materials and create a profile for that filament.

8

you can change Flow % in the slicer yes but that has its own issues.
Best to get it dialed in as close as you can with a default pla that you use allot of then “IF” any adjustments are needed for other materials to do that via the flow %

9

Mods can we pin this or add it to e-step calibration a must thread. Important info for those of us w DX.

1 Like
10

The Snapmaker G1 command does not accept a T parameter.
https://wiki.snapmaker.com/en/Snapmaker_Luban/manual/2_supported_gcode_references#g0-g1-linear-move
Instead, select the toolhead before using the G1 command:

T0
G1 E100 F50
T1
G1 E100 F50

The M92 command is documented to accept the toolhead number as an argument, but setting the E-Steps with M92 sets the same value for both toolheads, regardless of which toolhead is selected (or not). The listed commands do not set separate E-Steps for each extruder (tested) (as noted in the post).
The documentation for M92 should be updated.
https://wiki.snapmaker.com/en/Snapmaker_Luban/manual/2_supported_gcode_references#m92-set-axis-steps-per-unit

Note the following empirical observations regarding G1 and toolhead selection parameters:

T1
G1 T0 E100 F50 ; extrudes T1 not T0
G1 T1 E100 F50 ; extrudes T1

T0
G1 T0 E100 F50 ; extrudes T0
G1 T1 E100 F50 ; extrudes T0 not T1
2 Likes
11

So should we not even bother with E-Steps for the dual extruder? Or should we just do 1 extruder and save that?

12

Judging from my own experience (statistics of one), I do not see a need to change E-steps with the dual extruder. The factory values were good enough. More important: E-steps calibration may even be the wrong approach - I recommend this video from CNC kitchen: Calibration Cubes are BAD! This is how you calibrate your 3D Printer — CNC Kitchen
The general message: Each filament is slightly different, and instead of calibrating E-Steps, you should have filament profiles that adjust the flow rate according to the specific spool of filament.
That said, with the single extruder E-Steps were off considerably for all filaments, so a calibration makes sense there to establish a baseline. For the DX I did not need to do that.
If you do it for the DX, I guess measuring both, left and right, and taking the average between both results would be my approach.

2 Likes