prints failing immediately..

[grievence]

I started using Rsilvers PLA FFF in S3d and it worked perfectly. I went through probably 5 or 6 prints with no issues. Yesterday I was out of town so I didn't use my printer at all; today I go to start a hemisphere piece (of which I already printed one with no issue) and it starts stringing slightly; the purge off the side of the plate keeps noodling up around the extruder. Once it gets on to the part it starts the first layer it tends to keep a tendril attached to the extruder and in general isn't as clean a print as it was. The biggest issue is when it get to the support it starts ripping it up and gumming itself down in pla.

at first I checked the leveling; all seems fine.
nothing I fiddled with settings wise seemed to fix it (I was figuring retraction but I haven't quite grasped how to set that correctly)
can there be something at the mechanical level that I need to check? even tried running old gcode I have sitting on the sd cards and it still does this.

[Tim]

If PLA is "noodling up" like that, sounds like you may have a bit of baked-in plastic partially blocking the nozzle. This is not necessarily causing the print failure, but it's a good candidate. Various solutions to this can be found on the forum. One simple method (after retracting the filament a bit) is to poke a wire up into the nozzle and work it around to get rid of the blockage. That only works if you have a good piece of wire about 0.3mm (I have a 0.3mm lead mechanical pencil and found that the little needle that they give you to clear out jams in the pencil works perfectly for the printer nozzle). If you have nylon filament or cleaning filament (I think that's exclusively from eSUN), that can also help get a clog out. Running your extruder up to high temperature (250 C max if it's a V3b, higher if it's a V4), you can potentially burn any PLA residue into ash. You can also remove the nozzle and do the same thing with a butane torch, although anything that requires removing the nozzle is more involved. Soaking the nozzle (preferably outside the house) for a while in a paint stripper containing methylene choride should dissolve the PLA residue, but hitting it with a blow torch is a lot simpler.

[grievence]

20150803_202153.jpg (110.16 KiB) Viewed 9098 times

tried clearing it out, reset the s3d profile i was using and still this happens.

the calibration cube prints out (mostly) fine, bottom layer seems to round the corners a little more than the rest of the ones that follow.

if i do manage to get it to not gobble up the PLA it lays down, it all goes to hell again as soon as it has to do something like supports.
(i'll probably edit the post with a pic of that once my phone charges enough to take pictures ^_^ )

[jimc]

your not sticking to the bed right. either you dont have the right adhesive or the bed gap is too big.

[Jules]

What kind of PLA is that? (I didn't know they made clear PLA?)

That noodling in your photo is something that I always see while the nozzle is heating up, there is always a little bit of leftover plastic in the nozzle from the previous print that oozes out - if you let it heat long enough, the little plug melts and the whole wad falls down. (Or you can reach over and grab it with your tweezers - usually the easiest.) Or you can extrude a few mm through once it is hot using the jog controls, and let it clean itself out. The noodling at the side of the bed during the purge is also normal, i grab it with the tweezers and gently let the weight of the purge pull it down to the side of the plate, instead of letting the wipe smear it across the bed. Keeps things a lot neater, and it only takes a second.

I also always run a skirt of 2 or three threads around the part to prime the flow, and get rid of any leftover globs that i might have missed with the tweezer pluck.

Supports are always hard to keep stuck on the plate, they have a miniscule footprint. But if your calibration squares are curling at the edges, jim is right and you probably don't have it stuck down well enough to start with. (If you are printing on bare glass, you'll usually see about half a dozen successful prints before you stop seeing successful prints on bare glass, and move on to adhesive of some kind. Hairspray or gluestick are the most popular choices.)

Things to try, in this order:

1. Heat the bed a little if you are not doing it now.....around 40°C during the print for PLA. Helps to keep things stuck down.
2. Check the gap - you might need to move the plate a little closer to the nozzle for the first layer. (You can do that easily with the Z-offset just to test it. I'd suggest incremental values of -0.03 until you get a perfect 2.0mm tall calibration square.)
3. Make sure you have good, even adhesive coverage, whatever you are using, and apply it while the plate is cool. PLA warps up when it cools and you need very even adhesive to keep it in place.
4. You can always add a brim to the design, instead of the skirt, and make sure that it extends far enough out to contact your support. It just gives the thin support columns more contact area with the adhesive on the surface so they are less likely to let go if they get bumped.

See if any of that helps.....all perfectly normal so far.

[grievence]

Thank you both for all this; been using plus painters tape but been applying while the bed is warm. Bed adhesion never occured to me outside of replacing the tape; that's about the one thing I haven't had issues with until this point lol

edit: as far as the clear PLA is a no name I found on amazon for 15 a spool; not horrid but certainly not the best. breaks easily and it's rolled in such a way it can't be left alone or it will kink up. I mostly picked it up simply because I assumed I would be learning on it.

Also the supports in this case are needed as it holds up the internal of a hemisphere; flipping it didn't work out as well as I wanted to.

[jimc]

you know i thought the same thing when i first started printing then shortly realized the crappy cheap filament was just screwing me up and making the learning curve worse. fast fwd 2.5 years later and a good spool of filament has come down from 50-60 bucks to 20 bucks. its not worth messing with the no name garbage. its just going to confuse you because your results are going to be inconsistent and all over the place. there are many suppliers making good filament and reasonable price. esun, push plastic, b3d and even makergear's has come way down in price.

[Jules]

Thank you both for all this; been using plus painters tape but been applying while the bed is warm. Bed adhesion never occured to me outside of replacing the tape; that's about the one thing I haven't had issues with until this point lol

edit: as far as the clear PLA is a no name I found on amazon for 15 a spool; not horrid but certainly not the best. breaks easily and it's rolled in such a way it can't be left alone or it will kink up. I mostly picked it up simply because I assumed I would be learning on it.

Also the supports in this case are needed as it holds up the internal of a hemisphere; flipping it didn't work out as well as I wanted to.

I never could get PLA to stick consistently to plain painter's tape, and man did i ever try. You might want to snitch a can of hairspray from the wife's medicine cabinet. It works a whole lot better.

The reason that i asked about that clear looking filament is that it looks bubbly to me - might just be the angle of the photo. PLA is extremely sensitive to humidity...if it's old and has been exposed to too much moisture in the atmosphere, it develops bubbles and becomes very brittle and breaks at the drop of a hat. It's an exercise in frustration simply trying to print it, much less trying to do it while you are learning.

You don't have to waste that roll - if you put it into a sealed bucket or tub along with a bag of rice with a bunch of small holes poked in it to let the air in, for a couple of weeks, it might dry it out enough to get less brittle. (And after you've opened a spool of PLA, you'll want to store it in the bucket with the rice when you're not using it. Particularly critical if you live in a humid area. Like me.)

You do want to print that hemisphere with the flat side down and the round side up. It's going to look like crap if you try it the other way, even with support. (That's just the nature of PLA - it's lousy on overhangs without a considerable amount of additional cooling.) You can't use the brim if the support needs to be on the inside of the shell, so you'll need to try the other things to get the support to stick better.

And jim types faster than i do....ROFL!

[grievence]

I am quickly coming to find that beginners luck was just setting me up. I would have a hell of a time removing the prints from the tape. as far as storage I have been keeping my rolls in a container; haven't been using the rice but the bin has stuff built in to keep out moisture..... the excetion being the roll that has probably stayed on the printer for a few days..... so I'm sure that's a large source of my frustration as well

Either way I've underestimated the m2 as well; it's printing the piece pretty well without any supports at the moment.