need idea for end script

For some time my end script have looked like this:

M104 S0 ; extruder off
G91; Switch to relative coordinates
G0 Z10; Move up 10mm
G90 ; absolute positioning
G0 X125 ; Park in middle
G0 Y235 F5000 ; Move Y to middle of bed cooling fan
M42 P11 S255 ; Turn  Bed cooling fan on
M106 ; cool off nozzle
M190 S30; set bed and wait to hit target
M42 P11 S0 ;Turn off bed cooling fan
M140 S0 ; bed off
M107 ; carriage fan off
G28 Y; home Y
G28 Z ; Home Z
M84 ; disable motors
M81; power off

now the strange thing is that as the bed comes close to the 30 degree setting the LED on the bed starts to flash just once every 5 sec or so. this was not a problem until last night where the temp never reached 30 but it was arround hovering arround 39

are there better and more "foolproof" ways to do the same? 

the bed cooling was should not be misunderstood as a part cooling fan. the bed cooling fan is only used after the print is done to cool the bed down faster.

could i use M226 so that it will just wait forever for me to push the knob on the LCD ? or is the command in repetier different?


  • i was thinking of adding my bed cooling fan to pins.h and use M106 to set a thermostatic trigger

    but i would still need a kind of wait on the temp so the bed stays in front of the fan until its cool enough
  • ahh i have been blind

    M190 S30; set bed and wait to hit target

    needs to change to

    M190 R30; set bed and wait to hit target

  • i found this

    so now my Q is how do i mod the code to accept the R paramter?
  • M190 S30
    is correct. No idea what R should de. M190 is already wait.

    Problem can be depending on heat controller. Everything else then bang-bang will get spikes of heating especially PID and dead time, so these can be very hard in low temperature regions.

    A more safe solution would be
    M140 S0
    G4 S60

    With G4 wait adjusted to what it needs to cool down normally to be below 30°C if no spikes occur.
    This will always succeed and is also faster from missing spikes.
  • R is when you want to cool of the bed. or the oposite of heating

    i know the G4 method but i dont want to use that if i can avoid it
  • instead of G4 is there a command for waiting that i click the knob on the display?

    i could live with that ie it just runs the bed cool down fan until i click the knob
  • No interactive gcodes, sorry.

    M190 S30 
    will wait for cooling. Problem is that PID/dead time are optiimized for hot temperature and at low temperatures a smaller time is needed to go up a bit. Therefore these spikes have more effect and makeing it harder to reach the +/-1°C corrdidor for target temp.
  • hehe.... the lowest temp i see is arround 39

    oh well G4 it is.... i could go to marlin but man their list of issues are like sticking a hand i a wasp nest
  • Have you already tried heat manager 0 instead? That should go down smoothely to 30°C. The bigger swings on target temp are not so important for the bed and can be ignored.
  • edited September 2017
    hehe... i found out the issue...

    bad thermistor, it gave up last night and caused a decouple error

    i'm now tinkering with replacing it with a thermocouple so i dont have to take the bed assembly apart every 3 months or so

    i used G4 as a temp. fix but the thermistor must had one leg in the coffin as it did not last more than 30% in to a 20 hour print

    will open a new post for the thermocouple idea
Sign In or Register to comment.