So, I’m still trying to dial my printer in and am having issues with the first layer sticking. On short lines it sticks fine, but on long lines is peels up and scallops. I’ve tried various temps on the extruder and the heated bed, replaced the glass/PEI with just a cheapo glass piece and am still having the same problem. I’ve Zero’d out my Z with the paper trick numerous times and have adjusted my print start both up and down in the Z direction. I just can’t dial this thing in. Any ideas since I am totally out of them? My next idea is to get a BLTouch to zero out across the bed but I don’t think that’s the issue (but I could be wrong).
On small parts, its fine - it’s just on bigger parts with long, unbroken extrusion runs. It almost seems like the extruder itself as it goes past an already put down line is somehow sucking up the line it had just put down. Once about 4-5 lines get sucked up, the next line lays down ok and then the process repeats itself. Too hot maybe? I’ve been turning my temps up, maybe I should try turning them down? In the pic below, the temps were at 77 bed and 209 extruder at the time when I stopped the print (I stopped it on the long scalloped section). I had started this print at 73 and 205 and turned them up a degree as I saw the problem occurring. I let it make a few more passes to see if the problem went away and when it didn’t I turned them up another degree. Maybe I should be turning them down? I’m just at a loss at this point.
The paper is for leveling. Same as the BL Touch. The pictures look level.
As for Zero, the pictures look well placed. Spaces between lines would be too far away and a rough surface would be to close. Anything in between that should work fine.
I separate those two things because they are very different, but both of yours look perfect.
That leaves surface, temp, and speed.
You do not mention filament type (chemistry)? First layer speed? Print fan?
I’m using Hatchbox PLA (it’s all I have). My speeds are the ones that you give as examples on the extruder page. Print fan is Not on for the first layer (I have it come on with other layers). I’m running another test right now using all the default settings that you list for Slic3r and will see how that turns out. I’ve monkeyed around with enough stuff that I want to go back to a baseline and start from there.
Thanks for responding and letting me know that my Z seems to be fine and it’s a slic3r issue more then anything.
The reason I was leaning towards some kinda temp issue, is that my perimeters Always stick just fine, it’s only when it starts to fill in long lines between perimeters (or other features) that I see the scalloping.
Could I see the underside of these prints? Also a video of this happening might be helpful. Can you test to see if there is any air moving across the print as it is doing the first few layers. You want to make sure there is 0 air flow until you are up a few layers. Maybe tape a tiny string or something near the nozzle to see if it moves in a draft or is still.
I agree from this picture it “looks” like it is level and at a good Z height. What filament type and brand is this? Do you have any others to test? Have you cleaned the bed with isopropyl? Any oil from hands can cause spots where the bed doesn’t stick.
Have you tried printing the same part on a different part of the bed? Is it always peeling up on the same part of the print or the same spot on the bed?
So, in my new test with all of the default settings, I’m getting the same problem but a little worse. I clean the glass between every print with Denatured Alcohol to remove any oils. I have moved to other areas of the bed and the same thing happening.
Here are a couple of pics of the bottom of the print and a couple videos of another print I just did.
Great pictures and video. The underside looks good in the first two. The third picture looks like there isn’t enough actual surface contact. Meaning you can see that the round bead is only partially smashed flat against the glass. So I would suggest lowing the z a little to smash that down a little more. You want the bottom to be about 95 % in contact with the bed.
Onto the videos. Great videos very helpful. It clearly doesn’t get enough adhesion to the bed to let it stick in the first place. So we know it isn’t a problem where it lays down a good bead then comes along later and knocks it loose or something. So we need to improve the actual adhesion when it touches the bed.
Try the following.
lower the Z a bit to smear the bead into more contact with the bed.
Try lowering the bed temperature. It may be so hot that the filament melts right off of it. Try this in increments of about 3 degrees. Go as low as 50 and see if it makes a difference.
Check for air flow. I have seen kind of curling up when air is flowing over the print. It causes the filament to cool on top faster than the bottom so it curls up. We have seen a case or two where the cooling fins on the hot end cooler are pointing the wrong direction. So instead of blowing air out the sides it was blowing air up and down causing similar adhesion issues. (Kelly did you ever fix that or are you still using the tape to block it?)
We will will get this figured out. One step at a time.
What I see is that the adjacent previous pass is pulling up the new pass. I don’t see the adhesion issue on the thinner strands or where there is more time between passes for the newly extruded filament to cool. Based on that, I’d look at the factors that affect the cooling of the prior extrusion, particularly bed temperature and cooling fan. I think Aaron’s comment (quoted by thesfreader) is a reasonable place to start.
What I see is that the adjacent previous pass is pulling up the new pass. I don’t see the adhesion issue on the thinner strands or where there is more time between passes for the newly extruded filament to cool. Based on that, I’d look at the factors that affect the cooling of the prior extrusion, particularly bed temperature and cooling fan. I think Aaron’s comment (quoted by thesfreader) is a reasonable place to start.
That first layer looks too fast. I print at 30-35mm/s and I have the first layer set to 50% speed, no fan until layer 3-4 (not a big deal just not layer 1 for sure.
Yup a tiny bit less gap would help a bit.
I have my bed at 63C first layer a few less after that.
Agree with all of the above, clean bed, I have mentioned it before somewhere but you might want to try a magic eraser with Windex for a first real good scrub then just alcohol after that. On PEI I do the magic eraser thing about once a year.
You are really really close, for some that first layer really is a killer but I promise you are close. What you are seeing used to be acceptable a few years ago, not anymore. You can get it really nice now.
Thanks for all the input everyone! I’m off to have family dinner at my mother’s house now but will put these suggestions to work this evening and will let you know how it goes.
I use isopropyl alcohol to clean up but had been using the 70% stuff and getting bad scalloping. Switching to the 95 percent (or whatever it is) seemed to fix that part of my puzzle. Switching to glass has proven to be the ultimate win for me but you’re already there.
On this dinosaur I didn’t catch it at the time, but later I looked closely and saw exactly the same thing as in your video.
[attachment file=94346]
One thing to check is the height of your first layer. Some slicers have an option to make the first layer thicker, and if your layer heights are a bit thick to begin with, the first layer height can begin to approach your nozzle size. In such a case the extruded plastic is just barely smashed against the bed. It’s a long shot but if your first layer multiple is say 150%, then try setting it back to 100%.
Hmmm, I don;t think it matters much on the first layer but I am using 218 (on all layers) for my PLA I think it was 213 when I used hatchbox, but I know it still works as I printed a roll the other day.
I would venture that the first-layer height of 0.32 is pushing it for a 0.40 mm nozzle. If it were me, decreasing that one value to 0.25 or less would be the first thing I would try.
So, here is my latest test print - 75mm square, 1 layer height with the settings I posted above but with my temps set to 65 bed and 200 filament. It definitely is better but still not where I want it to be. The first pic is the top and the second is the bottom (while the print is still on the glass plate). In the second pic, ignore that strange whitish spot, it’s actually a small chip in the bottom of the glass (what do you expect from a Walmart 8x10 picture from that cost less then $2)…
Yup, nothing on it. Just wiped down with denatured alcohol and then printed.
I have a PEI sheet on a Borosilicate Glass plate but I swapped it out for this cheapy because I noticed that the PEI has very small “bubbles” between it and parts of the glass - at least that’s what it looks like, not total adhesion (I think).
Shoot I have no idea how much of my advice is valid. I use PEI, if you end up switching back tiny bubbles are okay, some don’t even need to heat it to use it with PLA.
