GCODE Question - Starting fan  

RE: GCODE Question - Starting fan

AFAIK Chuck you are only able to turn the fan on at layer 10 in the GCODE file with M106, then switch it off with M107.

Can set the speed, etc but C++ commands are intended only for the Firmware, sure the printers are only able to interpret marlin GCODE commands as per the following format.  Set Fan Speed | Marlin Firmware (marlinfw.org)

I could be wrong, it has been known before 🙂

RE: GCODE Question - Starting fan

That command (followed by {endif}) will insert M106 at layer 10. That will stay in effect until changed. Hard to say when it might be changed though, esp. with variable cooling in the slicer.

So you want cooling fan off above layer 10?

RE: GCODE Question - Starting fan

Hmmm, so you can custom code C++ into a GCODE file.

Interesting, well I'll be a monkeys uncle

Thought Bobstro would know the answer, clever lad 😉

RE: GCODE Question - Starting fan

It's very limited, but yes. Some notes and links here.

RE: GCODE Question - Starting fan

@bobstro

No.  Not layer 10.  I was using this as an example.  I am print nose cones with ABS.  The tip is always messed up.  I found that if I manually turn the fan on for the last 10 layers that it prints perfectly.  I just need to insert that in the Gcode.  I need to figure that out by determining the number of layers.  

RE: GCODE Question - Starting fan

I found the easiest way to do this was use the minimum layer time cooling settings. Observe the layer times as your print heard the tip, and have it kick cooling on for the quick layers. I've got some notes on doing this in my PPE printing notes. It's a manual process unfortunately. If most of your cones are similar, you should be able to find a good range.

RE: GCODE Question - Starting fan

"nears the tip". Stupid short edit window.

RE: GCODE Question - Starting fan

@bobstro

That is perfect.  I will try that.  It is much easier than GCODE.  

RE:

I know this is an old post but the issue persists. No way to turn the fan on at a certain level easily.  

in after layer change g-code insert this:

;LAYER:[layer_num]

M106 S{if layer_num >=4}54{else}0{endif}

Fan off, then after layer 4 it will run at 20%

hope this helps someone who lands here from a search!

RE: GCODE Question - Starting fan

Isn't better nowadays to use in PrusaSlicer Filaments > Cooling?

Or slice, right click on the vertical line on the right and as custom gcode there? It will be added before the specific layer starts.

There are so many more options there nowadays...

RE: GCODE Question - Starting fan

Unless I did something wrong, I could not figure out how to get the fan to start at 20% and then ramp up to 30%.  It always started at 0 and ramped up to whatever your maximum was.  The minimum was always ignored.  

RE: GCODE Question - Starting fan

I just tried it with a Voron Switchwire profile, and it worked as advertised. first 4 layers off, then ramped from 20% to 30% at the end.  There is something in the Prusa i3 MK3 profile that is turning off the fan.  I will have to investigate further.