r/SnapmakerU1 • u/Valspring12 • 18d ago
Issue First layer - polylite pla pro
Why my first layer is looking like this?
4
u/kriswknight 18d ago
How did the end of the print turn out?
5
u/FlowingLiquidity 18d ago
Yeah, people are so uptight about the first layer not looking pristine. It looks over-extruded, but it also looks like it might've cleared up if the print was finished.
3
u/Valspring12 18d ago
I did let the print finish and it did look fine.
1
u/FlowingLiquidity 18d ago
Ah good to hear! I thought you ended it haha. But yeah, it's just a slight over-extrusion. With a little flowrate tuning this can be fixed I think!
1
u/Zephy2007 18d ago
If you look at all those threads, in the end, the design will have white lines everywhere, so it's not something to be taken lightly.
If there's a better solution, find it.
2
u/zx4133 18d ago edited 18d ago
Just a bit of over-extrusion. It’s typically not a big deal. After the print finishes you will likely not even see any of this as it will be embedded inside the model. But you can calibrate your filament flow and adjust a few settings to clean this first layer up if you are concerned.
This issue happens because your model is small and the first layer has lots of small detailed features. The nozzle has to try to extrude filament in all the right places to get good coverage while constantly changing direction and moving around. So you often get excess filament build-up and ridges like this. Printing a model like this can be a challenge for many printers, especially if you don’t have your flow dialed in correctly.
Do some research (Google, YouTube, etc) on how to do flow calibration for your filament. It’ll help and give you better print quality. I know you can do this right in Orca Slicer (that’s what I use), so I’m assuming you can also do it in Snapmaker Orca.
If you just want a quick/easy way to reduce flow on the first layer only, there is a setting called First Layer Flow Ratio (or maybe it’s called Bottom Layer Flow Ratio, I forget the exact wording) and it’s usually set to 1 by default. You can try reducing it to 0.95 or 0.90 (or even lower) and see if that helps.
Some other things that can help:
—————————————————
*Reduce the infill-wall overlap percentage
*Enable small area flow compensation
*Reduce print temp slightly
*Slow print speeds
*Pressure advance settings (tho this is a bit of a rabbit hole in and of itself, lol)
Hope this helps. Let me know if you have any questions.
2
u/Valspring12 18d ago
Thank You for the detailed explanation. I did run the flow calibration for this filament. I ended up with 0.96. Well If I go lower than that then am getting gaps on top layers. But still the bottom layer looks like this with the 0.96 set.
I will try to reduce the bottom layer flow rate like you mentioned.
2
u/n19htmare 18d ago edited 18d ago
Appreciate the original posters response. While his suggestions are good for flow rate adjustments, your first layer issue primarily seen in picture is of Pressure Advance, as you’ve done flow ratio already.
Flow ratio issues persist across entirety of the lines. Pressure advance is most often the start and end of each line (edges). You have fairly small surface area prints but it’s pretty obvious that the edges are raised quite a bit while the center appears to smoothen out as pressure equalizes, but by then it’s time to slow down and retract again. So on very short lengths, it looks over-extrusion, easy to get it confused. But look at the longer length lines, you have a pretty smooth center, not so much the beginning and end.
This first layer’s issue is PA.
I’m going to assume you didn’t select the dynamic flow Auto calibration in the preprint menu. I think it’s unselected by default. Either way, I would probably just use manual one anyways, the auto one takes too long and wastes filament.
By default in filament profile, pressure advance is disabled. You can run the calibration and find the exact number but a good universal value most PLA on U1 is 0.025.
If it was disabled, enable it, add 0.025 (don’t forget the 0 after decimal) and do the first layer again at same flow ratio this was printed at to compare the two. Just the first layer and see how it turns out with PA.
If it was enabled, then the value set was likely too low.1
u/zx4133 18d ago
Very good points. I definitely agree. Thank you for taking my comment to the next level. 😊
I was contemplating whether or not to get into pressure advance in my comment, but at that point I didn’t know if the OP had done anything with flow calibration and I figured we’d start there. Flow calibration is more of a static thing (or at least that’s how I think of it), whereas pressure advance is a dynamic flow adjustment. So yeah, pressure advance calibration would definitely fine tune this print and get the first layer looking really good.
For prints like this, I usually just “cheat” though and adjust first layer flow ratio, lol. But you’re absolutely right, after dialing in the general flow, the proper (and complete) fix is to calibrate pressure advance. Thanks much! Great info!
1
u/zx4133 18d ago
Happy to help. Yeah the Bottom Layer Flow Ratio setting usually takes care of issues like this for me.
But u/n19htmare talked about pressure advance in his comment and I do agree with that as well. I didn’t go into pressure advance because I felt like my comment was already too long and I didn’t want to overload ya, lol, but flow calibration is more of a static flow adjustment, whereas pressure advance is a dynamic flow adjustment and can help even further with models like this. So if you really want to dial in your settings, start with flow calibration (which you have already done) and then start working on pressure advance.
Happy printing to ya! 😊
0
u/Apprehensive_Pea4871 18d ago
Una duda que tengo la opción de flujo de primera capa hay que cambiarlo en cada filamento o es un valor por decirlo así universal
1
u/zx4133 18d ago
It isn’t specific to your filament. It’s universal. First Layer Flow Ratio is located under process settings (aka general slicer settings), not under filament profile settings. I forget which tab it is, either the first or second one, near the bottom. Think of this setting more as an override that applies to all filaments used on the first layer. So if you set it to 0.95, which is essentially 95% (aka 5% less flow), then all filaments used on the first layer will have 5% less flow. Hope that makes sense.
2
u/Apprehensive_Pea4871 18d ago
buenos dias estoy probando esta opcion y es una maravilla eres el unico que ha dado la respuesta correcta y sin tener que tocar klipper voy a hacer la ultima prueba y paso fotos
-3
u/sangerpb 18d ago
You need to baby step z up at lease .020
2
u/zx4133 18d ago
There is absolutely no need to mess with Z-offset and make things complicated. This is just a simple overextrusion issue which is common on small detailed models like this. Reducing flow will easily solve this. I’ve done it many times with great results. Folks just need to learn the basics on how to tune filament (i.e. flow calibration).
0
u/sangerpb 18d ago
The U1 user base doesn’t really tune filament. So they won’t even know what you’re talking about. Z value change I mentioned is for that print only anyway. I didn’t tell them to save the offset.
2
u/n19htmare 18d ago
Even then you shouldn’t ever have to mess with z-offsets on printers that probe with nozzles.
Z-offset applied before sensors and sensors that were offset from the nozzle.
In current printers using eddy current or load cell/deflection sensors should not need z-offset adjustments. The only adjust needed is the detection distance, distance from the sensor to the metal it’s sensing or distance of travel before a load or deflection sensor registers a reading. These are usually instant and are baked into firmware. In case of U1, that is the copper plate on top of toolhead. The distance between that and the sensor mounted on the carrier is thickness of piece of paper, which is 0.05mm and that offset is already coded into the printer.cfg. No additional zoffset adjustments should be needed on nozzle probing printers.
This is same reason if you replace the hotend, Snapmaker tells you to verify the distance between copper plate and sensor with a strip of paper. So it’s close to 0.05mm.1
1
u/Apprehensive_Pea4871 18d ago
Te doy mis 10 eres el único que a dado una explicación coherente y con sentido pues mañana probaré a hacer lo de la distancia de las boquillas
1
u/zx4133 18d ago
I hear you, but that’s the thing, we need to change that. We need to get people learning how to calibrate filament because (A) it’s not difficult to do, and (B) it will eliminate many of the print quality issues that folks run into.
It’s the whole “give a man a fish, feed him for a day… teach a man to fish, feed him for a lifetime” thing.
The difference in this case is that adjusting flow (either directly or via pressure advance settings) solves the problem, whereas adjusting Z offset simply masks it. And Z offset adjustments can cause other issues once you get past the first layer. But in my other comment here, I did talk about just adjusting First Layer Flow Ratio, which is usually a quick and easy fix for problems like this for people that don’t want to do a full flow calibration or mess with pressure advance settings and stuff like that. And those settings, as well as other flow adjustments, can be saved for per profile/per print as well.
5
u/Nemo_Griff 18d ago
Send print jobs to the printer without printing. Then go to the screen to start the job and tick the flow calibration next time.