Jamming during ironing with flow at 0%
I found a case today where my Prusa MK4 jams. Ironing is turned on and output flow is set to 0%.
If jam detection is turned on, the printer pauses and requires reloading the filament. Lasts for about 2 minutes before jam detection occurs again.
But if jam detection is off, the heat creeps into the copper section and creates a clog.
Clearing the clog requires:
- Removing the nozzle (while extruder is hot)
- Loosen the thumb screws on extruder
- (If installed) Removing the "Nextruder" e3d v6 adapter from the heater block (using included wrench)
- The clog can be melted away into liquid using a torch. The flame is put on the brass side.
- Push a straight piece of rod (cut from a clothes hanger, about 1.85mm) to clear the liquid plastic.
- Wipe off the rod with tissue until no more plastic coats the rod. It will be very hot.
I hope that helps anyone in a similar predicament.
0% flow rate will almost always jam; you are keeping filament stationary in the hot end and overcooking it.
15% - 20% should be enough to protect the hotend from jamming.
Ironing is one of those functions that sounds like a good idea and many people clamour for but which no-one who owns a sheet of sandpaper should ever consider.
Cheerio,
RE: Jamming during ironing with flow at 0%
Maybe if the flow rate is very low during ironing, the filament should partially retract to avoid jamming.
That would make certain that whatever remained in the hot end was thoroughly overcooked and ensure a partial clog.
Buy some abrasive paper and give up ironing.
Cheerio,