my hex hot end is clogged with HIPS, ive tried leaving the heat on and forcing more filament through but but there is absolutely no movement. i cant do cold pulls or anything. what do i do? ive had this printer for 2 days now and havent had a single print yet. :’(
I got myself into the same situation. In the end I took the nozzle off, cleaned it and put it back on. It was easier than I thought except for putting it back on, it is very easy to strip the thread inside the heater.
If there is no filament flow at all:
1.) Turn temperature up to 250C and allow nozzle to reach temperature.
2.) Open extruder idler.
3.) Pull Filament out of the extruder.
4.) Trim off end of filament.
5.) Push filament back down into the extruder and see if you can get any filament out. You can push fairly hard against the extruder to get this to work.
6.) Pull filament back out, see if there is anything stuck to the filament and trim off again.
7.) Repeat process several times to see if you can get nozzle flowing again.
If there is flow but it seems partially blocked, thin or is coming out of the nozzle all twisty:
1.) Using either HIPS or PLA turn your nozzle to the proper temperature for that material.
2.) Once up to temperature, extrude several mm of filament.
3.) Turn your temperature down, for HIPS use 140C
4.) Once the temperature is reached, open the extruder idler and pull out the filament.
5.) You should have a perfect mold of the inside of the hot end. The end of the filament should taper to a cylinder that is the size of your nozzle and have a nozzle sized cylinder that is about 1mm long.
6.) Check for foreign particles or gaps in your mold of the nozzle.
7.) Repeat steps as necessary to clean out nozzle.
If you can’t get filament into the hot end, use the filament as a depth gauge to determine how far into the extruder/hot end it can travel and post a picture showing that.
This is what he means by “mold” of the hotend… Adjust your “pull” temp until you get there. For the PLA I run, I extrude at 225 and pull at 120 to get this result.
Edit: This example came out of an E3D V6.
Thanks for the pics and the step by step. Nice thread.
Hi, all! I’m working with a Mini and the extruder seems to be clogged and pigtailing HIPS. I’ve tried heating it up to pull it out, then about 10 cold pulls at various temperatures, from about 140 to 190, but mostly around 160. I’ve heated up to 240, extruded, then cooled down to 160 and pulled it out, but nothing. I see a little tiny notch in the filament; could that indicate something lodged in there? How might I unscrew the nozzle without taking off the entire hotend?
Thanks!
That looks like the filament is just snapping… Nozzle may have cooled off too much.
Heat the nozzle to 165C+ to remove from the heater block. Use a 17-18mm wrench on the heater block and a 7 or 8mm wrench or vise-grips on the nozzle. The nozzle will be hot so make plans ahead of time… I put a silicone pad over the print bed for protection also.
To re-attach the nozzle, heat the heater block to 165 and carefully finger thread the nozzle. Brass is soft, so make sure not to cross thread.