Printing PCL G code?

Hi Guys

I’m trying to print PCL on my Ender 5 plus .6mm nozzle.
Does anyone know how to change the g code so I can print at 140C
I have tried this : M302 S120 But the lowest it goes is 150 C
Using the Prusa slicer.
Do I have the added code in the right spot ?

G90 ; use absolute coordinates
M83 ; extruder relative mode
M104 S150 ; set temporary nozzle temp to prevent oozing during homing and auto bed leveling
M140 S{first_layer_bed_temperature[0]} ; set final bed temp
M190 S{first_layer_bed_temperature[0]} ; wait for bed temp to stabilize
G28 ; home all axis
G29 ; auto bed levelling
G1 Z50 F240
G1 X2.0 Y10 F3000
M104 S{first_layer_temperature[0]} ; set final nozzle temp
M109 S{first_layer_temperature[0]} ; wait for nozzle temp to stabilize
M302 S120
G1 Z0.28 F240
G92 E0
G1 X2.0 Y140 E10 F1500 ; prime the nozzle
G1 X2.3 Y140 F5000
G92 E0
G1 X2.3 Y10 E10 F1200 ; prime the nozzle
G92 E0

When printing a mug the first 5 layers or so go down looking great. Then it’s like the layers start to cool down and contract pulling the printed item slowly off the print bed.
Maybe I just printing toooo hot ?


Welcome to the forum! :slight_smile:
I don’t think this is a g-code limitation, in this case you would need to push new firmware allowing nozzle temps to go that low. The hardware is limiting your printer from extruding at all below certain temps. Hope this helps!

Hi Sam

Thanks for your input.
Any any ideas on changing the firmware?


Hi Mike

The Firmware limits are set within the firmware and will not allow the extruder to rotate until the EXTRUDE_MINTEMP is reached.

Building firmware can be a bit of an adventure but it is something you would need to undertake yourself. It’s actually only a small change but then you have to recompile it.

Within the Marlin firmware, you will be able to search for the variable mentioned above and you will locate it pretty quickly, Below is an example;

// @section extruder

  • Prevent extrusion if the temperature is below EXTRUDE_MINTEMP.
  • Add M302 to set the minimum extrusion temperature and/or turn
  • cold extrusion prevention on and off.
    #define EXTRUDE_MINTEMP 170

Hope this helps

Hi Jason

Thanks for the info.
I have had success using M302 S110 and changing the startup nozzle temp from 150 to 120 in the g code.

But not having much luck on getting the PCL to stick to any type of build plate at any temperature.
Got one mug to print on a rough textured magnetic stick on plate from creality on an Ender 5 plus. Can’t get it to do it again :frowning:
Got any ideas ?
I even glued fine sandpaper on the print bed, but no luck. Paint tape, glue stick, heated bed, not heated.
The first couple of layers look so good. Then it looks like the PCL shrinks and pulls off the plate. Tried rafts as well.


there was a particular Nylon we were having issues with and one of the owners suggested a glue slurry to help with adhesion. It was something like 60/40 Elmers white glue and water, Paint it on the build plate, apparently, you need 4 or 5 layers for it to work properly, Adhesion was no longer an issue, Removing it from the build plate after it was done that was another story.

If PCL handles like ABS with the shrinkage factory try a trick I used years ago, Bag the printer. I used a clear recycling bag and once the print was started I pulled the bag loosely over the top of the printer to hold the heat. It’s not for insulating it, It was to prevent cross breeze across the bed. This helped with my ABS printing big time.

Hopefully one of those may help you out.

Hi Jason

Thanks for the reply.
I like your bag up the printer idea.
Think I will pass on the super gluing. I not much into a big cleanup.


Usually for the most part the curling on the edges is just from a breeze hitting it while its printing. Starts to curl then it just falls

If you can keep the ambient temp stable curling becomes less of an issue

Ok then. Plastic bag it is :slight_smile:

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