M106 GCODE with Fan Index

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radensb
Posts: 47
Joined: Sun Jul 23, 2017 3:21 pm

M106 GCODE with Fan Index

Post by radensb » Sat Mar 09, 2019 12:12 pm

I wanted to write some custom gcode that controlled the individual extruder fans independently. I cant seem to get this to work. Each fan seems to be wired to its own fan control on the mainboard and the Marlin page shows how to control individual fans with the M106 command:
http://marlinfw.org/docs/gcode/M106.html

So I tried:

Code: Select all

M106 P1 S255
M106 P2 S255
M106 P3 S255
Nothing works. Sending just M106 turns both fans on to max as expected, but I can't control individually using P<index>. Am I not indexing properly? Or is this something that is not enabled or something? If so, Why??

Thanks!

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mwester
Posts: 85
Joined: Sun Nov 26, 2017 8:02 pm

Re: M106 GCODE with Fan Index

Post by mwester » Sat Mar 09, 2019 12:54 pm

I'm presuming that your printer is a TAZ, with the two extruder fans on each side and the hot-end cooling fan on the front of the print head, right?

The cooling fan on the front is hard-wired to the +5v line, and cannot be speed controlled nor turned off -- and that's a good thing.

The two extruder fans on either side of the print head are wired together, so they act as a single fan. They cannot be controlled independently.

radensb
Posts: 47
Joined: Sun Jul 23, 2017 3:21 pm

Re: M106 GCODE with Fan Index

Post by radensb » Sat Mar 09, 2019 2:22 pm

I'm presuming that your printer is a TAZ, with the two extruder fans on each side and the hot-end cooling fan on the front of the print head, right?
Sorry, I should have been more clear. Yes, I have the Dual V3 on my TAZ 6.
The cooling fan on the front is hard-wired to the +5v line, and cannot be speed controlled nor turned off -- and that's a good thing.
100% agree. Again, I should have been more clear.
The two extruder fans on either side of the print head are wired together, so they act as a single fan. They cannot be controlled independently.
I looked up the mainboard and see that there are several fan connectors: Fan 0, Fan 1, Fan 2, 5V Fan
Image
Fan 0 and Fan 1 seem to correspond with Heat 0 and Heat 1. Fan 2 is the case fan and 5V Fan seems to be the fixed common cooler block fan.

The schematic of the mainboard (RAMBO 1.3) shows that each fan is independiantly controlled by the microprocessor.
(MOSFETS section in the middle)
Image

So, the hardware supports individually controllable fans. Even if they were wired together, I would think that I could still control that fan index (and both fans would respond the same), but none of my

Code: Select all

M106 P<index> S255
commands yeilded any response at all. I am running 1.1.9.34 (current Lulzbot Cura 3.6.3 firmware). Could this be disabled in the firmware??

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mwester
Posts: 85
Joined: Sun Nov 26, 2017 8:02 pm

Re: M106 GCODE with Fan Index

Post by mwester » Sat Mar 09, 2019 4:29 pm

Ah - the dual extruder -- yeah "details" like that are important! :D

My post assumed the standard single extruder with the dual fans -- it's not pertinent to your situation, so please ignore it entirely.

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