Unexpected tool change in version 1.04
Hi,
I have IDEX printer that still runs 1.04 version of firmware. I know, I need to upgrade it, but it is my only working printer at the moment and I don't want to mess up with it
For quite some time I was not using IDEX functionality and had 2nd extruder disabled in the firmware, but recently I began to work on a project that requires many identical printed parts and to save time I reflushed firmware and enabled 2nd extruder and ditto mode.
Everything works fine and I can print 2 identical pieces at the same time. However, I started having occasional failures when printing with only one (left) extruder. All the sudden printer switches to right extruder as if T1 command was sent and that ruins the print because the second extruder is not heated. Tonight I got "lucky" - the failure happened at the very beginning of the print and the entire part was printed with right extruder. The problem however is - that extruder was loaded with a filament of "wrong" color. The same gcode file executed 2 more times after that run correctly and the parts were printed with left extruder, as they should.
My starting code in Cura for single extruder prints contains M280 S0 in the very 1st line to make sure ditto mode is disabled and my understanding is unless T1 command is sent, the right extruder should remain idle.The only reason of such failures that I can think of is communication errors between Octoprint and the mainboard, but they are extremely rear and the chance that certain command will be understood as T1 is even smaller.
So the reason of this post is to ask if anyone has experienced this and what was your solution/workaround.
Thanks
Comments
If you enable echo (M111 S7) firmware will write back received commands. Together with logging it should be possible to track how exactly it happens if you know the time or just search for T1 in log. Then it is also sure a command send is the reason and not some internal thing changing extruder id. Not that I have heard about that happening regardless of old firmware or not.
I wonder what is happening there as I see so far no T1 or B0. Might be interpreted as binary command but without correct checksum which is required in binary format as I think it should not execute it. Will check later the fimrware source regarding checksum test in binary format.