Sudden change in print quality...  

RE: Sudden change in print quality...

@sturmkraehe

I wouldn't attempt to heat PLA beyond 250degC you'll start breaking down the PLA in the nozzle and if you have a clog it will just get worse depending on the mfg the PLA will breakdown inside the nozzle and with no flow you will get the junk building up really fast. If you can still extrude I use cleaning filaments as they are easier and gentler than all the other options and it has worked for me for ~2+ years now with no clogs with a little being used every two to three spools of the same material and every time between material/mfg changes. They are used to clean extruders in injection molding machines and they have a wide functional temperature range and are very "sticky" and pickup all the junk that can build up inside the nozzle. (If you see little black flecs in the cleaning filament extrusion its getting junk out) This method only works before a total extruder jam.

If you have melted filament suck in the heat break/heat sink side your going to have "fun" clearing it out if it is jamming up everything. 

RE: Sudden change in print quality...

It is a total blockage and I feAr it could be in the heat brake, but I won’t know until I get a chance to work with it. I used cleaning filament almost two spools ago and did a cold pull with nothing showing up on the end. I found a Prusa tutorial for replacing the inner sleeve of the heat brake. I’ll go that route if necessary, but would prefer not having to disassemble the extruder if possible.

RE: Sudden change in print quality...

Posted by: @sturmkraehe

It is a total blockage and I feAr it could be in the heat brake, but I won’t know until I get a chance to work with it. I used cleaning filament almost two spools ago and did a cold pull with nothing showing up on the end. I found a Prusa tutorial for replacing the inner sleeve of the heat brake. I’ll go that route if necessary, but would prefer not having to disassemble the extruder if possible.

Before you tear anything down, try this:

1. Raise Z to max.
2. Open the extruder door.
3. Locate a 6in/15cm length of 1.5mm brass rod. A hex wrench may work but will be short.
4. Heat the nozzle up above printing temps.
5. Insert the rod down through the filament feed at the top, down past the Bondtech extruder gear and into the PTFE.
6. See if you can gently push any stuck filament down into the hotend where it'll melt and extrude out.

If that doesn't work and you can feel a blockage, try keeping it at temp and:

1. Remove the nozzle and clean out any loose filament.
2. Holding the rod with pliers, slowly insert it from below giving it time to heat up and soften the blockage.
3. See if the blockage pops up into the extruder area where you can grab it with tweezers or needle-nose pliers.

I've managed to avoid tear-downs for clogs using this procedure many times. Be sure to brace the extruder with your hotend and don't twist it on the frame as you press up or down.

RE: Sudden change in print quality...

I will try this, thanks!