I got this machine last night and went through the setup documentation meticulously. Everything seemed to work as it should and I even got a few small prints out last night. I’m using Lulzbot PLA filament. This morning it won’t extrude consistently and tends to curl up right as it comes out of the nozzle. Could my nozzle be clogged already and if so, what steps should I take to clear it? I’ve already used a piece of wire from a wire brush and pushed up in there and did a few cold pulls but it still doesn’t want to extrude correctly. I thought it may have something to do with the hobbed bolt but even when I push the filament manually it still happens.
You can do a forum search for “nozzle clog” and similar terms and you’ll find some good ideas.
Also (I grabbed this from someone else’s post) here’s Lulzbot’s instructions for clog clearing: https://www.lulzbot.com/support/unclogging-tips .
One thought (since I don’t know your experience level): The TAZ5 comes with ABS still in it. When you switch to PLA you have to leave the extruder at ABS temperature as you feed in the PLA until you’re sure the last of the ABS is out of the head. Then lower the setting to PLA temperature. Otherwise some ABS may be left in the nozzle, since ABS won’t melt at PLA-melting temperature.
Or you could use eSun’s extruder-cleaning filament in between, it’s good at both ABS and PLA temperatures.
Another thought: Is your idler bearing spinning freely when it’s swung back and not touching the filament? If not, that’s the first thing to fix.
Ok - so I have followed the instructions at that link and done around 5 or 6 cold pulls. It did improve some but then got worse again. As the filament extrudes with the nozzle raised quite a bit on the z-axis it doesn’t fall straight down as it should. I know what it’s supposed to look like because the first night I had it everything worked great. The filament now shoots out slightly thinner it seems and it comes out at a slight angle which sometimes works ok and other times just makes a nice bird’s nest right at the tip of the nozzle. I’ve tried various temps for the PLA ranging from 185 to 210c or so, with mostly the same results. It’s pretty clear the nozzle is blocked in some way. I’m just not sure what is safe to do to clear it other than cold pulls. I am a total noob and I followed the instructions exactly and so on my first extrude with the PLA I did not heat up to 230 to purge the ABS. That’s not to say that the ABS didn’t come out - it definitely did - but I can’t swear all of it did.
Also got some cleaning filament on the way. Thanks for that tip.
Clean the tip of the nozzle also.
To clear the possible leftover ABS, pull out the filament. Heat the nozzle to 245C for a minute, then set the new extrusion temp to 220C. Immediately try to manually push PLA through the hotend with the idler open. Try to do this before the nozzle gets to 230C. This should thoroughly liguify any residual ABS… The PLA should liquify pretty readily to push it the ABS.
Careful not to damage the nozzle opening by jamming anything solid in to clear… The brass is pretty soft.
My filament often doesn’t fall free and straight either, but once I tug on it as it comes out or otherwise clean up the balled-up mess on the nozzle it then falls straight and continues falling straight. So I just don’t worry about it if it doesn’t always fall straight, since not doing that at the start doesn’t seem to reliably indicate a blockage. Just my opinion, for what it’s worth.
Ok. So I’ve got it going now for the most part. Z-stop was too low and was causing part of the problem and I also had a partial blockage that several more cold pulls seemed to clear. I got a few good prints, but now I’m getting this. I really don’t know how to describe it, but the bottom layer just doesn’t seem to be going down correctly. See images. Does anyone know some potential causes of that? Thanks in advance everyone.
I doubt this is it but I’ll mention it anyway:
Immediately before I start a print I always do a couple of 10-mm manual extrude operations, to make sure the extruder head is full and is really flowing properly. It basically replaces the amount of ABS that oozes out at the end of a print or when the extruder is heating up before a print.
Often I find it’ll take almost half of a 10-mm extruding operation before the filament starts coming out of the nozzle at all.
Your problem seems to be longer-lasting than that, but doing that just before kicking off a print might help some.
You also might change your skirt to be three or more layers wide, again to be sure the plastic is flowing well before the extruder starts on your actual part.
Oh, and I’d wait a couple of minutes after the extruder says it is up to temperature, to let it get uniformly heated throughout the nozzle, before starting any extruding or printing. That may be belt-and-suspenders, but again it might help.