Great Prints at 0.25mm, 0.20mm; failure at 0.10mm

[Marshall]

I came across some M2 FFF profiles on Thingiverse that apparently saved me, because the first two seem great with what they have so far printed (profiles specifically for PLA). I mean they look as good as the included M2 prints with the printer, at 0.25mm and even 0.20mm layer height. But when I use the 3rd ("high-quality") PLA profile in the group using S3D, set for 0.10mm layer height, here is what I can describe that I see repeatedly happening:

On the larger layers, the "priming" injection comes out, wipes the nozzle on the Y bed edge, then simply goes to town. When I change it to the 0.10mm profile, he has the heat set the same (V3B set at 225C, bed at 60°C), but what I see is the priming ooze before print begin to curl around back into the tip and stick, every time! So it attempts the scrape the excess, drags a gob with it on the nozzle, and then it's a stringy net with no adhesion from there and I have to kill the print. I'm not sure why the nozzle appears to be a magnet for a glob just because layer height is set different but then again, something else is likely happening, such as the tip "plowing" through what's laid down. I've wiped the nozzle clean quickly before it tries to do a small cube print at 0.10mm layer height. Doesn't work. Same situation, stringy mess everywhere as soon as it begins laying material.

My bed is leveled. The thicker layers lay down just fine with no bottom warp. No tape at all used--no Kapton/mask. I realize, I need to use the Kapton/mask at some point of course. What I'm trying to figure out, is why 0.20mm layer height (MGear blk PLA) prints excellent, and at 0.10mm height MG PLA cannot even start. I'm thinking the first layers need to be at 0.20mm, then quickly transition into 0.10mm layer profile after 1mm or so height to maybe do this right.

I read how to choose the FFF profile for so many mm of print layer height, then set a profile 2 to kick-in when that pre-set height is reached. Here: https://www.simplify3d.com/support/tuto ... f-a-model/

Though I feel on a 25mm x 25mm x25mm cube I'm printing, one FFF profile should work from the bed start to finish, right?

I'm open to trying all of the above or any suggestions, but mainly I'm wondering what others' take is on this--what is the most efficient way to get thin layers to start on the plate correctly? Is it due to too little adhesion, most likely no Kapton use?

I did try green frog masking for it, was a no go, but then heard mask isn't always great for PLA. So I'm thinking I need to simply go with the Kapton I have, but want to rule this out first so I'm not using it for nothing. What's contradicting, is that I am using no added adhesive, and getting excellent print starts to finish with larger layer heights. Could that just be due to more PLA actually biting the glass with thicker layer heights, though? That is what I feel, personally.

How do I increase the amount of "rings" around the part base in S3D (at the very start of the part print), so that maybe I get a more consistent beginning layer unstrung with loose PLA? Does bed heat need to rise with smaller Z starting layers?

Yes dazed and confused I am. Thank you for the help fellow members. I will be here to stay. Nice to meet you all!

[jsc]

Low layer height prints require much finer adjustment to the first layer height to print. You have a few options:

1. Since you are printing fine at .20mm, you can just set your first layer height to be .20mm. You certainly could use a second process to do this, but easier just to set First Layer Height to 200% in the Layer tab.
2. You can calibrate your first layer height setting with a test print and a caliper. Follow the links here: viewtopic.php?f=3&t=2262#p12140

As for getting filament dragged behind after blobbing, the easiest way to fix that is just to be standing by with tweezers when it primes and grab the filament as it is priming so you can make sure it all gets left behind.

[Jules]

As for getting filament dragged behind after blobbing, the easiest way to fix that is just to be standing by with tweezers when it primes and grab the filament as it is priming so you can make sure it all gets left behind.

Yep! It works! I actually do that before it even gets going out of the nozzle during the priming purge, if you catch it right, you can coax the purge out into a long thread and nothing at all winds up on your skirt. (And i'm still at the hovering over it stage anyway. )