[3D Print Stops When Cooling Switched On]

Hi Greg.  I think I've discovered what my issue is.  The cooling fan is cooling the nozzle down too much, and that stops the print since the heater cannot get the nozzle back to 250°.  I did wonder why it had got further inside my enclosure before stopping instead of the making one lap and stopping now I've opened the enclosure door........

 

The reason I want cooling on is that I get awfully lumpy ABS prints when making a large surface area part and the nozzle ends up dragging across the surface and has caused layer shifts where the belts has jumped when the nozzle can't get past.

 

But now I'm thinking cooling won't help since the previous layers are already hard enough to make the nozzle bump along.

 

I've replaced my start and end gcode with yours and will try pulling back on the flow rate compensator to see if that helps with the lumpy top surface issues.....

[3D Print Stops When Cooling Switched On]

Hope someone can help with this.....

 

When I turn on cooling in Cura, my print stops after approximately 1 minute.  For example I have a print roughly 15cm by 6cm in ABS with a 15mm brim and it only does around 3 laps of the brim and the printer stops.  The printer just hangs and I cannot stop or pause the print.  The only way to get control is to turn the printer off and on again!  When I turn cooling off the print runs fine.

 

I also have a minimum layer time but that just gets ignored too.

 

My printer is an Anycubic i3 Mega, and I'm using the latest Cura version.

 

Cura print and printer profiles attached

 

Start G-code

G21 ;metric values

G90 ;absolute positioning

M82 ;set extruder to absolute mode

M107 ;start with the fan off

G28 X0 Y0 ;move X/Y to min endstops

G28 Z0 ;move Z to min endstops

;G29

G1 Z15.0 F600 ;move the platform down 15mm

G92 E0 ;zero the extruded length

G1 F200 E5 ;extrude 3mm of feed stock

G92 E0 ;zero the extruded length again

G1 F{speed_travel}

M117 Printing...

G5

 

End G-code

M104 S0 ; turn off extruder

M140 S0 ; turn off bed

M84 ; disable motors

M107

G91 ;relative positioning

G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure

G1 Z+0.5 E-5 ;X-20 Y-20 F{speed_travel} ;move Z up a bit and retract filament even more

G28 X0 ;Y0 ;move X/Y to min endstops, so the head is out of the way

G1 Y180 F2000

M84 ;steppers off

G90

M300 P300 S4000