M302 not working

XYZ_123

Hello,
I'm trying to the set minimum temperature to allow extrusion and retraction using M302.
M302 S120 R120
but it's not working .
Firmware version :- 3.4b3

deckingman

@dp_23 said in M302 not working:

Hello,
I'm trying to the set minimum temperature to allow extrusion and retraction using M302.
M302 S120 R120
but it's not working .
Firmware version :- 3.4b3

It's working for me using 3.4.0 (final).

XYZ_123

@deckingman Ok, But in my firmware version it's not working.

deckingman

@dp_23 said in M302 not working:

@deckingman Ok, But in my firmware version it's not working.

Suggest you upgrade to the latest stable version then.

XYZ_123

Reference: M302 not preventing cold extrusion for Gcode
@dc42 : Please confirm if this holds true for 3.4beta3 version , when extruder is driven via expansion board? i.e. if extruder is connected to expansion board, M302 does not come in effect for enabling minimum extrusion temperature.
if i wish to have this working, is there a way to change in source code and achieve this?

deckingman

@dp_23 I say again - M302 is working fine with the latest stable firmware (3.4.0) - I've just double checked. To be clear, this is with hot end heaters connected to expansion boards. The extrude and retract buttons are greyed out in the UI until all heaters associated with a tool reach the threshold temperatures as defined in M302.

Now, you have two choices. (1) Upgrade the firmware from the beta version you are using to the stable version, or (2) persist with your request for the source code to be changed for the non-stable beta version. Best of luck with the second one.

JayT

@deckingman @dc42 :

I have used heater channels from 3MB 6HC-Mainboard for extruder, but extruder motor & BTT is connected on expansion board. Now if I wish to configure M302 to avoid cold extrusion, will it work?
OR I have to configure heater & corresponding sensor on Expansion board?

dc42

@jayt cold extrusion prevention is not yet implemented on extruders driven by expansion boards. See https://docs.duet3d.com/en/User_manual/RepRapFirmware/CAN_limitations#temporary-limitations.