ASA fails to extrude after a PLA print  

RE: ASA fails to extrude after a PLA print

I have had clogging and clicking noises from the nextruder recently too.

Result was under extrusion and smoke on the nozzle, cause was an eSun mate PLA filament, no idea what was wrong with it but i threw it away after i confirmed it what it causing me the trouble...

Solutions are Cold Pulls, Needle in the nozzle and if all fails remove the nozzle from the heat break and mechanically or chemically remove what was stuck inside.

RE: ASA fails to extrude after a PLA print

Posted by: @samael

I have had clogging and clicking noises from the nextruder recently too.

Result was under extrusion and smoke on the nozzle, cause was an eSun mate PLA filament, no idea what was wrong with it but i threw it away after i confirmed it what it causing me the trouble...

Solutions are Cold Pulls, Needle in the nozzle and if all fails remove the nozzle from the heat break and mechanically or chemically remove what was stuck inside.

I ended up having to heat an extruder using my hot air rework station to clear the nozzle from a very persistent clog. It happens. And some times it's just not easy to clear the problematic filament from the hot end. Since this was an obxidian it was worth a bit of effort. Lots of heat and a noclogger.

RE: ASA fails to extrude after a PLA print

Thank you for your reply.  I am also using an ObXidian 0.6 HF.  I have 2 other printers so no clue what made me want to even run PLA through this one.  Is there an article explaining the process you used or can you describe in more detail?  Is it as simple as using a  Heat gun and a nozzle cleaning needle?  

Thanks Again,

David

RE: ASA fails to extrude after a PLA print

I seldom run PLA  But when I do, I generally run cleaning filament through it at 290C. 

RE:

I cleaned a 0.6 HF nozzle recently from moderately-higher-temp filament residue. The exact steps I use:

- Controls, set nozzle temperature high enough for the stuck material to be liquid (doesn't need to be optimum printing temperature) e.g. 270° C

- While it's heating up, feed PLA as fast as it will go (which is 1 cm / s max. limited by the UI). If the extruder clicks, slow down.

- When it flows freely, click "Cooldown" then continue feeding until in PLA printing temperature range (so the PLA inside the nozzle doesn't get "overcooked")

- Set to 100°C and let it cool

- Open the extruder idler and gently pull the filament as far as it will stretch (too much force and it will snap)

- Set temperature higher and keep pulling gently. It will take only a second or two to come loose

- The "pulled" filament should show the internal three-pronged structure of the HF nozzle, and any foreign material it caught

- Repeat if needed until it comes out clean

Needles can easily damage HF nozzles, careful. I'd stick to the "on-board" tools with front panel controls for as long as making some progress. But I've had to also clean the cold end of nozzles with a 2 mm drill where it wasn't possible to get the PLA into the hot zone anymore (I'd avoid this as it will probably scratch the nozzle's inside surface finish).

RE: ASA fails to extrude after a PLA print

You are more or less describing a manual cold pull procedure, in my case the automated one fails to extrude and to clean the nozzle.

How are you feeding the filament? I want to try it out. 

Posted by: @mnentwig

I cleaned a 0.6 HF nozzle recently from moderately-higher-temp filament residue. The exact steps I use:

- Controls, set nozzle temperature high enough for the stuck material to be liquid (doesn't need to be optimum printing temperature) e.g. 270° C

- While it's heating up, feed PLA as fast as it will go (which is 1 cm / s max. limited by the UI). If the extruder clicks, slow down.

- When it flows freely, click "Cooldown" then continue feeding until in PLA printing temperature range (so the PLA inside the nozzle doesn't get "overcooked")

- Set to 100°C and let it cool

- Open the extruder idler and gently pull the filament as far as it will stretch (too much force and it will snap)

- Set temperature higher and keep pulling gently. It will take only a second or two to come loose

- The "pulled" filament should show the internal three-pronged structure of the HF nozzle, and any foreign material it caught

- Repeat if needed until it comes out clean

Needles can easily damage HF nozzles, careful. I'd stick to the "on-board" tools with front panel controls for as long as making some progress. But I've had to also clean the cold end of nozzles with a 2 mm drill where it wasn't possible to get the PLA into the hot zone anymore (I'd avoid this as it will probably scratch the nozzle's inside surface finish).

RE:

yes, correct, it's "cold pull".

For routine maintenance (when the nozzle still works somehow), load filament by the usual procedure.

If this fails, open the idler (the lever in the Nextruder that presses the filament against the Nextruder wheel). Insert filament (I usually put it in through the regular opening via the "Festo" on top but through the idler door would probably work. 

Pushing it through the nozzle manually - not using the Extruder - might actually be closer to a "standard process" for unclogging, see Diem's other post a few hours ago. Next time I might actually skip using extruder controls, this could save some time.

RE: ASA fails to extrude after a PLA print

I just checked, fumbling in the filament through the extruder door takes longer than pushing it in through the vertical path.. might be a question of convenience e.g. if you can access the printer from the left side more easily than mine (which stands against a wall).

RE: ASA fails to extrude after a PLA print

Thanks, i will give it a try!