Help with inconsistent first layer and curling
Printing with PLA, stock settings at .1mm layer height. I printed this in the center of the build plate. This printer has been printing fine but this one single object is tossing it for a loop and I'm not sure why. Now my benches seem to get screwed up as well. I reset to factory, recalibrated, redid V2Calibration and still this. The file is attached, I did a high resolution so it would be easier to see.
First thing, the lower right(edit: corrected) curls after a few layers, but this has a good first layer section. Second thing is why the entire edge has a good first layer and the middle does not. I honestly don't get that at all. Third thing, is why is the center like that. Clearly it is extruding enough if the sides get plenty, why in the middle does it crap out?
Do I have a warped bed? If I do, is this under warranty, I've barely owned this thing very long. This problem is kind of throwing me for a loop and frustrating me. Ultimately I would like to solve the first layer inconsistency first, because I can solve the curling with glue stick I bet, but solving that too would be nice.
EDIT: My apologies, it is the opposite corner that curls first, but it still has a good first layer in that section so I'm still confused. Also, fingerprints are after I was looking at it off the plate, the plate was thoroughly cleaned with alcohol before printing.
Re: Help with inconsistent first layer and curling
is your alcohol 99.9% pure?
lower purities sometimes include castor oil... which will not aid adhesion.
is the other side of the model, smooth, or rough, I am guessing rough?
it looks like you are too low on live z, or over extruding, or both
what is your first layer, layer height?
0.2 is usually ok
try again, whilst the first layer is printing,
watch the surface and if it starts forming ripples, this will indicate there is too much plastic in too small a space. to resolve thisreduce the negative value for live'Z'
the correct setting is when your first layer is smooth and is entirely unique to your printer
The link below may help
https://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/life-adjust-z-my-way-t2981.html#p61629
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Help with inconsistent first layer and curling
Top is pretty smooth TBH. The issue with live z is, if I go too far down, the sides of this print get WAY to much PLA, whilst the middle gets just enough. If I tune it for the sides, the middle craps out like this. I'm starting to suspect there is a concave section around the center probe point. This would actually explain A LOT about other issues I've seen, and why I can't seem to get z height perfect. Also this is .1mm layer height.
You say to reduce negative z height, but if I do that, the center of the print might not even touch...
Re: Help with inconsistent first layer and curling
I'm going to grab some better alcohol at the store today, when I get that I'll do this
This should tell me if the bed is crap or it's me, it will also make it much easier to calibrate.
Re: Help with inconsistent first layer and curling
Did the above test and results were not good. If I back the nozzle off it just gets less and less adhesion on the middle section, so everyone and their mother who is saying I'm too close, YOU ARE WRONG. It is always higher on the edges than it is in the center, regardless of the nozzle height I choose. This is a bed issue, and the GLORIOUS pinda probe can't handle it apparently.
Re: Help with inconsistent first layer and curling
it's probably warped, just put a straight edge (ruler will work) and see. you could also take it off and check too, it could even be the mounts that are off tolerance or the Y plate itself. getting a new bed that is less warped (these PCB's aren't perfect, so don't expect glass flat) is ideal. worse case is you could try and shim the center with 0.1mm shim washers. technically you could print them too, but buying them is a perm solution.
note on the pinda.... it doesn't correct much in terms of bumps. mostly tilted Y, or Z.
Re: Help with inconsistent first layer and curling
Thanks for your reply. I tried doing bed level correction, and I got close but I need more than 50um, which is the max the correction allows. I found a thread from long ago that said the pinda probe may be too high. My probe was causing the nozzle to touch in the back right on first bed level. I moved the pinda probe as low as it can safely go, and I'm doing a reclaibration now. Hopefully this solves the issue, or gets me close enough a bed correction of 50um will work.
If not I hope prusa will ship me a new one, not sure how long the warranty is... I've barely owned this thing though. It would give me an excuse to upgrade to 3030 extrusions because shipping from czech republic is undoubtedly slow.
Re: Help with inconsistent first layer and curling
Whelp, I think I have finally resolved this, and it was a hurricane of issues.
First, the power supply was pulling on the Z frame. There is a half a centimeter gap between the power supply and the frame at its closest. If I move the Z frame back to it, the Z frame is not far enough forward to reach the priming zone. I have left it disconnected and will likely just toss some padding in there if it starts to rattle or vibrate. For now it is hanging on the black piece connected to the Y frame.
Another issue is the display cover. It needs to be shaved on the bottom. The display cover bottom is LOWER than the bottoms of the corner printed pieces. This was also causing the frame to warp.
These two issues were why the frame as leaning and warping. It took me taking the entire thing apart to figure it out.
Now on to the thing that is my fault. My assumption was that this was supposed to look like glass on the bottom. It isn't. It's supposed to be consistent without gaps. Something I discovered after putting it together and the z height being too high, was that the layering was consistent. Once I got the nozzle too far down, the issue I originally had presented itself again, albeit not nearly as badly.
So I got to thinking about why this happens. Well on my prints, the nozzle starts in the lower right hand corner filling in the first layer. In the OP, it would be lower left because it's flipped upside down. The only reason the layers fuse is because the nozzle is hot, and the time between two lines connecting is so small (it's a corner). This is also why they fuse on the edges, because the nozzle is hot and the time between two lines in the edges is short. However, the time between lines in the center of the print is long. When the nozzle is too close, it can't fuse to cover everything, because the previous line has already solidified, so it pushes UP, and makes it APPEAR as though the line is thinning. Also giving the illusion that one side of the print bed is lower than another.
Upon pondering these revelations I began to back off until the top of the first layer was smooth (nothing pushed up). No corner looks like glass and it is very consistent now.
I think the key to the first layer is you want to start with the lines the same size on the bottom, then slowly push down to fill gaps. I think if I had known the bottom of the first layer doesn't need to be glass I could have figured this out sooner.
In any case the issue is resolved now. I still hold that threaded rods are trash. My first order now that it's printing again is to print 3030 extrusion pieces and order some extrusions. I'm tired of the y frame warping, I'm going to solve that issue with a sledge hammer if I have to.