Interaction between T0, T1, M114

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b-morgan
Posts: 175
Joined: Fri Aug 11, 2017 8:53 am

Interaction between T0, T1, M114

Post by b-morgan » Sun Oct 29, 2017 3:16 pm

I just installed a dual extruder on my TAZ 6 and was having a problem with the calibration print using Cura 2 Lulzbot Edition beta and Marlin 1.1.5.19 which led me to perform the following experiment. First, I installed 1.0.2.22 and switched to Cura 21.08. I then issued these commands manually:

(home, set absolute, auto-level etc.)
T0
G92 E0
T1
G92 E10
T0
M114 ;Show position of first extruder
T1
M114 ;Show position of second extruder

Since the description of M114 says "Get the current position of the active nozzle. Includes stepper values", I expected the first M114 to return E0 and the second M114 to return E10. Instead, both return E10.

Since the test/calibration print works (in 1.0.2.22), I'm assuming that the Marlin firmware is properly maintaining the E values for each extruder internally. I just can't see it on the outside. Are there other commands I should be using?

The test/calibration print "fails" in 1.1.5.19 as the start gcode retracts both extruders, wipes, auto-levels, and then attempts to reset both extruders back to zero. T1 is successful, T0 doesn't move. The T0 portion of the first layer is printing air for a quite a while before the filament actually reaches the nozzle again. I'll report this as a bug as soon as I develop some confidence in my method.

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