@infiniteloop @OwenD
Thank you both for all of your help. I've implemented changes and I am not getting errors any more. I wont be able to print until tomorrow due to severe weather in my area.

But I wanted to post the scripts below to make sure I am not missing anything.

At the end of config.g
global move.extruders[0].position=0.0

; daemon.g
; Constantly runs in background to check outputs etc
;
M98 P"filamentmonitor.g"

; filamentmonitor.g
; Check filament progress, feed pellets if needed
if job.file.fileName == null ; no job file around?
M99 ; exit
if {{global.filamentProgress + 11500.0} <= move.extruders[0].position} ; 11500 mm are done? Then …
set global.filamentProgress = {move.extruders[0].position + 11500.0} ; … prepare for the next meter
M106 P0 S255 ; … start the compressor (fan 0)
G4 S3 ; … wait 3 seconds
M106 P0 S0 ; … stop the compressor

; start.g
; runs immediately before any slicer created gcode
set global.filamentProgress = move.extruders[0].position

I am not sure how you are posting gcode script so mine is just copied and pasted. There are proper indents after the if statements in my files.

@infiniteloop
I created a test macro that just opens the air valve for 3 seconds and closes it. It worked great.

When I implemented the suggested changes to the config.g file start.g file daemon.g file and created the filamentmonitor.g file I am getting an error notice.

#1 - M98P”0:/macros/filamentmonitor.g”
Error: in file macro line 9 column 43: meta command: array index out of bounds

I am not sure if I am getting this error because it is conditional on the start of a print and the print hasn't started yet.
Thanks for you help.

FYI - after some testing the compressed air system pushes 75g of pellets every operation cycle, which equates to 9500mm of extrusion.

@infiniteloop
Thanks for your help. I am going to attempt to write up some code tonight and implement in the morning.
I think checking every 10 seconds will be fine. The way I have the feed tube set up right now there will be a certain amount that goes from the large hopper to the tube. This is determined by gravity and a bend in the tubing. The compressed air just pushes it from holding to a small hopper at the extruder. (I don't want to have too much weight with the extruder). I plan to do some experimenting tomorrow to figure out exactly the weight of the pellets/blast and then calculate the weight of plastic extruded out of my 2.75mm nozzle and use that for the mm of extrusion.

Thanks for the help. My build is a 3000x1500 build. I think by the end my build volume will be 1000x2400x1000. I am using a re3d pellet extruder and so far am printing around .75kg/hr.
Here is a link if you want to see my latest video talking about some of the components.
https://youtu.be/e6AMm3SlXuw

Hello,
For my giant cartesian printer I need to create a macro and Meta to open a compressed air valve every 1000mm of extrusion to feed the pellets to the extruder.

Running a Duet 3 6HC. I have the compressor triggering off of a SSR which I have wired to out 7. I have that output configured to Fan 0.

I was hoping:

M106 P0 S255 B3;
M106 P0 S0

would turn it on for three seconds and turn it off.

Is there a delay gcode that I could add in-between the two 106 commands that would add a specific delay?

Then I need to start my research on creating a Meta code that will fire this macro every 1000mm of extrusion.

Thank you for your help.
-Kyle

@phaedrux
I am not. I am currently using 24ga wires. Did not know that thermocouple wires needed to be anything special.

Ill try that next.

Thank you

Hello, I could use some assistance. I am setting up a build using a DUET 3 HC6. I am installing a pellet extruder that is has three heaters with independent K-Style Thermocouples. I have the thermocouples ran to two daughterboards. I was able to get the heaters tuned but now when I move the Y axis my heaters fault and set to 2000 c instead of their actual temp.

I checked the wiring on the thermocouples.
I made sure the continuity is good.
I disabled the Y Axis and moved the extruder by hand to see if it would trigger the heater fault (It did not).
I've checked the wiring of my Y motor, everything is great.

Thank you for your help

below is the link to my config file.
https://docs.google.com/document/d/10XdfVg8JJ72Q2h5y4btkh5xpThhucuYZW2Qnh01Lk8I/edit?usp=sharing