Slow down printing as Z-height gets higher

Dutchprinting

Hi Guys,

Somewhere a while ago i read about a command in the config that could lower printing speeds if the Z reaches certain heights.
I want to implement this in my printer, is there anyone that can help me find this?

PS: i dont want to do this in the slicer as i slice at an angle and post process it for my 45" degree angled printing so the gcode will be weird.

Kind Regards,
Running 1x 6CH mainboard, 5x 1HCL, 5x 1XD at 3.5b4

T3P3Tony

@Dutchprinting there is not a single gcode command to do exactly this but you can use conditional gcode in daemon.g

The basic idea is have a while loop in daemon.g that executes every few seconds and checks the Z value from the object model. if its over a certain amount, make the required adjustment to speed using M220.

so for example, in daemon.g

while true
  if move.axes[2].userPosition > 10
    M220 S80 ;slow down to 80% speed
  G4 S5 ; wait 5 seconds before looping.

This assumes that your Z axis is Axis 2, if not adjust the index for move.axes[]

Obviously this is very basic and you could extend it to scale by a % of the Z position between some limits or add other logic

For more information on daemon.g see:
https://docs.duet3d.com/en/User_manual/Reference/Gcode_meta_commands#daemong

That page also has the documentation for meta Gcode which includes the loop, conditionals, comparison operators etc.

Dutchprinting

@T3P3Tony Thank you! i think this is the way, i didnt think about the Deamon file. i'm going to try it out and update this thread!