Taz V Nozzle Clogging

I just got my Taz 5 recently and only ran a few prints before it stopped working.

If I tell the Taz to extrude, nothing comes out as if the nozzle is clogged and the filament feeding mechanism just digs its teeth into the filament. I can force plastic through manually and it will come out the end of the nozzle slowly, but it takes much more force than it should. I tried three cold pulls with no results. I’m using some 3 mm ABS, I also tested another strand of 3 mm filament I had laying around. What other steps should I try to get my Taz printing again?

@garthbartin

You can try the cold pulls with PLA, it is allegedly more “rubbery”, though i never had any luck with this.

the first step after “cold pulls” is probably to remove and clear the nozzle.
1 - bring the hotend up to temperature and loosen the nozzle, then remove it when it cools.
2 - remove the filament and clean the hobed bolt with the small wire brush/ dental pick/ “compresed air”. If you dont the teeth of the bolt will be “blunt” due to the chewed away filament stuck in them. I always give it a good blow out with a high pressure compressed air generator.
3 - you can then bring it back up to temperature (because it wont extrude otherwise) and run some filament through without the nozzle. to clear out the hot end.
4 - While this is going on, soak the nozzle in acetone (you said you were using ABS? or D-Limonene {or apparently ®-(+)-Limonene} for HIPS or ?Methyl-Ethelene-Ketone {MEK} / Caustic Soda for PLA {not sure yet}). Give the jar a good shake twice a day or so, and attempt to clean it out with something that isn’t going to scratch the bore (eg a good quality cloth on a wooden scewer). you could use the blunt end of a 3mm drill bit by hand.
5 - Once the large bore is clear the only way i have found to reliably clear the nozzle tip is the blunt end of the appropriate sized drill bit (0.5mm, 0.35mm etc).
6 - stick the nozzle back on.

There are multiple other suggested ways. Heating the nozzle with blow torch/ heat gun/ solder iron/ oven etc but i have found the acetone and patience clears ABS the best.

You then need to figure out why… (which i am still working on!) … comes down to:
to much back pressure at nozzle or in bore
or trying to push it through to fast (print speed)
to soft filament to early (heat creep)
crappy filament
to much drag, spool binding
buildup of “discoordination”(???) - ie missing steps due to failure to calibrate e-steps correctly gradually clogging teeth
???Dust on filament (not sure about this one, but i’m reaching for straws myself)

When I got my TAZ5 I was surprised at how much pressure it takes to push a filament into the nozzle by hand, but that’s apparently normal.

Did you wait a minute or two after the nozzle reached proper temperature before trying to extrude anything?

You might check to see if the idler bearing that pushes the filament against the hobbed bolt is spinning freely when you move it completely away from the filament. Mine wasn’t, and I had to remove the arm it’s mounted in and clean out small support filament residue apparently left over from the making of that part. The stuff was in the small clearances between the bearing sides and its face also. If that bearing’s jammed, that would explain a lot.

Heh – I just got bitten by this myself this morning.

I’d recently switched from PLA to ABS (using the eSUN transition filament to clear out the PLA before putting in the ABS) and did two small ABS prints last night OK. This morning I tried to do a print and nothing came out, the hobbed bolt just dug its usual divot in the ABS. I pulled out the filament, blew everything clean including the hobbed teeth, put it all back together. Same thing.

Turned out during the change from PLA to ABS I’d not set the tension properly on the bearing that presses the filament into the hobbed bolt. It was set at 7-8 mm clearance between the two washer faces. Oops. I believe it’s supposed to be 5-7 mm. So I set it down to 5 mm, and no more problems. My problem sounded like your problem, so I’m hoping my solution will be your solution.