First layer trouble - inconsistent extrusion, lines not well adhered to each other
So I used to have a small degree of this before needing to fix my heatbreak being too far down / away from the PTFE but I just completed the fix for that (I think) and now I'm generally having really shitty extrusion in the first layer and not-ideal looking extrusion later. Photo is attached.
I've found that if I get the nozzle closer to the bed, it improves but then I get wrinkling and much further away than this and it doesn't actually adhere at all. Anyone have any suggestions on this?
Added complexity: using a 0.25mm nozzle. This attached photo is printed with a first layer of 0.2mm layer height.
RE: First layer trouble - inconsistent extrusion, lines not well adhered to each other
There's a general rule to use layer height of 75% of nozzle diameter or less. Your layer height of 0.2 with 0.25mm nozzle is too big. Lower it down.
If you use Prusa Slicer, you can add MINI profiles with 0.25, 0.4 and 0.6 mm nozzles right from setup wizard. Eah has its own printing profiles and will take care of additional things like layer height and extrusion width.
RE: First layer trouble - inconsistent extrusion, lines not well adhered to each other
So I'm using 0.2mm for the first layer height because that's actually what's in Prusa's provided presets for 0.25mm nozzles at all of the presets. I'll give 0.15mm a shot tho, thanks.
RE:
Hi Aaron,
can we please have a look at the other side of the test square?
are you trying to print on a smooth PEI Build plate or a Textured Build plate.
have you cleaned the build plate since you did the repairs.
I find washing My build plates promotes good adhesion. I use hot water with a tiny bit of Dish soap, and I rub it into the build plate really well, then rinse with hot water and dry immediately with plain paper towels.
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: First layer trouble - inconsistent extrusion, lines not well adhered to each other
Thanks for the tips - so I actually grabbed a picture and collected some more info and in the process stumbled on a solution for my first layer that was pretty unexpected as I haven't had to do this before, ever.
I needed to run the print fan on layer 1 and then I could also move the print head slightly closer to the bed (like a 0.020 adjustment). The filament was apparently remelting as the nozzle went by and curling. As soon as I did that, I'm back to smooth first layers.
RE: First layer trouble - inconsistent extrusion, lines not well adhered to each other
@aaronpedia
Interesting, it's good you found solution.
RE: First layer trouble - inconsistent extrusion, lines not well adhered to each other
It's taken me 7 hours to find this - finally getting a decent first layer! My i3 MK3S+ worked perfectly with PETG but when I loaded in some new PLA+ it was exactly as depicted in your image, extrusion seemed inconsistent but was fine on all other layers. I've ramped the fan up to 100% for the first layer, slightly increased extrusion multiplier and first layer height, and I'm finally able to get a good first layer. Thank you so much!
Original Prusa i3 MK3S+
RE: First layer trouble - inconsistent extrusion, lines not well adhered to each other
A brief update - while the fan helped considerably, speeding up the first layer also helped a lot - less time for the nozzle to push heat into existing material on the bed. After a temperature tower I also lowered the nozzle temperature (to about 20°C below manufacturer spec). I had previously slowed down first layer speed for some PETG, which seemed to be part of the issue. Either way, for anyone with an inconsistent layer who's tried the standard Z calibration and such, try speeding up and ramping up the fan! Fortunately this hasn't caused any issues for bed adhesion on the basic parts I'm printing.
Original Prusa i3 MK3S+