Dripping and curling extruder

[drivingon9]

Hi all,

New here after recently purchasing a M2 kit, and hoping to get some tips for some issues that I'm having.

I've printed several models already, and for the most part, they came out pretty well. What I'm having issues with, however, is within the crucial 2-3 seconds of starting the print. I typically, I need to restart a print about 1-5 times before the first layer to work, and not create a massive mess.

Here are two symptoms that I think are contributing to the issue:

1) When my extruder is brought up to temperature (215), it'll sit there and slowly leak/ooze out of the nozzle. I feel I need to constantly wipe it. At some point, presumably when the plastic in the nozzle is depleted, it'll stop slowly oozing out. If I don't keep it clean, when I start a print and the extruder moves to "home all", it'll blob the excess ooze onto the corner of the glass, leaving a chunk on the nozzle.

2) Whether the nozzle is "blobbed" or I keep it clean, when the printing start, the nozzle will routinely move off the plate in order to extrude a bit before it centers again to begin the actual print. When it starts to extrude, most of the time, it'll just curl up around the nozzle (sticking), creating a big blob right on the nozzle... Again, I need to quickly wipe this before the print starts (or, sometimes, grab the block and pull down so that the rest of the stream is going straight down away from the nozzle). At this point, if I haven't cleaned the nozzle quickly, it'll carry the big block and make a mess. if I've kept on top of all the wiping, there's a 1 in 3 (or so) chance that it'll actually start extruding properly for the first 2 seconds, instead of causing a stringy mess (which is typically corrected pretty quickly after a couple of seconds but, by then, there's all sorts of cross-stringing).

This is super frustrating.. If that first crucial 2 seconds extrudes OK, the rest of the print will typically work fine.

Someone told me that my exruder is getting clogged, and suggested pulling out the filament, and over heating a little until all the plastic has melted out of the nozzle. I actually tried this, and my next print worked great. But subsequent prints would go back to doing the exact same thing again, and I really don't want to have to go through the "cleaning" process after every print.

Any tips? Suggestions?

I appreciate your time... Thanks!

[Bratag]

Some ooze is normal. Your best bet is to do what a lot of us do which is to wait until the nozzle is moved to the side and extrudes a small amount, then grab your tweezers before it moves back onto the print bed and pull off the extruded filament. That being said - if you have your bed leveled and the z-stop set correctly , even if you don't do this , the wipe it performs should pull leave the extruded filament hanging off the side of the print bed. This of course leads me to my next point ... make sure your bed is level and you have the z-stop set correctly and or tweaked via the z-stop adjustment within S3D (or slicer of choice). Badly leveled beds/z-stop problems are responsible for MANY issues - including stringing when laying down that first critical layer.

Now if you are not getting a nice even extrusion when you say extrude 100. IE it blobs up all over the nozzle. You may have a blockage .... or you may just have a heavily crudded (yes its a word ) nozzle which is causing the stream to catch and stick to some existing plastic on the nozzle rather than coming out cleanly.

Grab yourself some eSun cleaner filament and run that through periodically, especially when switching filament types. You can also use a piece of it wiped over the nozzle to pick up stuck on plastic (obviously when hot).

There are a number of very good articles on the forum regarding bed leveling and making sure your extrusion multiplier are correct (another possible issue with stringing), I would suggest however you avoid the useless forum search and instead opt for google with

site: forum.makergear.com bed leveling

etc etc.

Your results will be much better.

[drivingon9]

Thanks for the quick response! Much appreciated.

I believe my z-stop is set OK.. I actually check it before every print (the nut sometimes jiggles loose and shifts the bolt enough to throw things out of whack).. I think my bed is leveled OK, but I'll double check.

When I just manually extrude, it'll sometimes stick to the nozzle and create a giant block, and sometimes flow fine.. I haven't figured out the conditions under which it'll pick one of those.

Anyways.. I just ordered the esun cleaner to see if that works, or not.

Thanks, again, for the tips.

[insta]

You can run your nozzle much cooler than 215, especially if you're using PLA.

I run eSUN black PLA at 180C on the V3a, the V3b is like 190C.

[jsc]

Just my two cents: I agree with Bratag. Oozing on warmup is normal. I just stand by with tweezers, do a quick grab before homing, and again during the purge just to make sure it's not curled up. If it just looped the end, that's pretty normal. If it's really clinging to the end and coming out all curly into a ball, that can be a partial blockage. Curling is caused by the end being caught by some baked on crud on the outside. jimc has recommended some wire brush or other that you can get at a hardware store to clean it off, but I wasn't paying proper attention. I just scrape off the exterior of the nozzle as best as I can with tweezers, or if it's really bad, very carefully try to wipe it clean with a very thick layer of damp paper towels. Don't burn yourself on the 200+ C nozzle.

If your bed is leveled and set correctly, and you are getting proper adhesion, the very first bit of filament that goes down on the glass should stay down. No ends curling up or anything. Since the first bit is generally the skirt, that's not super important but it's a good sign that everything is as it should be. If you are getting some lifting, apply some glue stick to the bed, works wonders. Also, check the extrusion calibration thread in the tips forum.

[insta]

You can also clean the exterior of the nozzle ... with the nozzle. Park the heated nozzle about 1mm off the bed and extrude 500mm of filament into it (it's not a huge waste -- you've probably used more filament for a dumber purpose). It will make an enormous blob that buries your hotend's nozzle. Now, let it cool on its own.

When you're at 80C (ABS) or 50C (PLA) just break the wad off with pliers and be amazed at all the gunk that goes along with it.

[drivingon9]

Thanks for all the replies!

I started playing around with lowering the temperature a little, and found that around 200 (instead of the recommended 215), when I manually extrude, I get nice smooth flow where before I would get a sort of rapid jittery flow.. It also lessened the oozing. That seems to add a little more consistency.

Glue stick on the glass made a huge difference, also.

I'll work on cleaning the nozzle next, as per recommendations to avoid more sticking/curling.

Again, appreciate the feedback.

[DrRobot]

You can also clean the exterior of the nozzle ... with the nozzle. Park the heated nozzle about 1mm off the bed and extrude 500mm of filament into it (it's not a huge waste -- you've probably used more filament for a dumber purpose). It will make an enormous blob that buries your hotend's nozzle. Now, let it cool on its own.

When you're at 80C (ABS) or 50C (PLA) just break the wad off with pliers and be amazed at all the gunk that goes along with it.

I tried this, but the bond is so strong that I couldn't get the thing off

[insta]

You can also clean the exterior of the nozzle ... with the nozzle. Park the heated nozzle about 1mm off the bed and extrude 500mm of filament into it (it's not a huge waste -- you've probably used more filament for a dumber purpose). It will make an enormous blob that buries your hotend's nozzle. Now, let it cool on its own.

When you're at 80C (ABS) or 50C (PLA) just break the wad off with pliers and be amazed at all the gunk that goes along with it.

I tried this, but the bond is so strong that I couldn't get the thing off

couldn't = wasn't willing