I need your help! - Tricky printing problem  

RE: I need your help! - Tricky printing problem

Additional information:

• 0.4 mm Nozzle
• I use prusaslicer with standard settings for PLA (215 ° C, 60 ° C) 
• The filamet used is Orange PLA Filament 1.75 mm from prusa shop, but the problem still occurs with other filaments with diffrent brands. 

RE: I need your help! - Tricky printing problem

I don’t know… you said you looked at lowering Live Z but this looks like a classic example of Live Z being nowhere near as negative as it needs to be. The strands of filament are not sticking together, so you’ll need to lower the nozzle. Also, from the first picture it seems like you’re using the textured sheet. While not impossible to print PLA on the textured sheet, it is trickier than PETG. But then again, I think you need to bring the nozzle down quite a bit. Just wondering… did you switch from a smooth sheet to a textured one? The textured sheets are quite a bit thinner than the smooth ones, which could explain why your Live Z is so off.

RE: I need your help! - Tricky printing problem

@fuchsr

The textured sheet came with the printer as it arrived, and that's what I've been using since. My gathering, as you can see at the third picture, is that some parts have the effects of the nozzle being low, and some effects, as you mention, of it being to high. Is that typical for a too high nozzle? Also when I do the z level calibration, lowering the nozzle produces highly squished filament as it petruds around the nozzle. I ended up with the earlier settings as I didn't find the result pleasing. But then again I'm not an expert. 

RE: I need your help! - Tricky printing problem

Just interested but has the mc been like this since build, or have you had good quality prints then it started with the issues?

RE: I need your help! - Tricky printing problem

@clarmrrsn

I don't quite remember, as I was a printer novice, but I know I wasn't impressed with the quility of prints. I'm certain though that the problem spans at least a month after I built it. It is  possible that it's always been there. 

RE: I need your help! - Tricky printing problem

Make sure you have turned 7x7 automatic bed leveling on, it’s what deals with unevenness of your sheet. 

Somewhere between where you are now (single strands not connected) and the overly squished filament you described there’s got to be a middle ground of perfection…

RE: I need your help! - Tricky printing problem

@fuchsr

I do have that feuture turned on at the beginning of a print. This is the strange part: I have experienced the two things simultaneously. At the first layer calibration for instance (the first image), some stick and look perfect, but others do not. It's just really weird and what I've battled with for so long. 

RE: I need your help! - Tricky printing problem

Indeed, I agree fusher

Try running through this live Z adjust procedure. I have not tried it yet but gets good feedback, persist with it till you get a consistently good first layer back to back prints.

I would check what it is like maybe 2 or 3 prints in a row without adjustment, if its different with no adjustment then maybe something is moving somewhere.

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

RE: I need your help! - Tricky printing problem

I don’t want to bash the textured sheet because I know folks have been able to get decent prints from it with PLA but I’ve found it to be quite temperamental. If you’re willing to invest a modest amount of money, I’d try the smooth Prusa sheet or one I’ve come to like, the BCZAMD textured sheet ( https://www.amazon.com/gp/product/B07XC673ZT/ ), which I found to work equally well with any filament I’ve thrown at it. Don’t know where you live, which one is easier to get your hands on. 

RE: I need your help! - Tricky printing problem

@fuchsr

I believe that this sheet produces good prints, but does this actually resolve the problem, as it appears to be quite specific. I also can't find a way to get my hands on just this print sheet, but it's possible for me to look elsewhere as I live in Sweden. I do appreciate your support!

RE: I need your help! - Tricky printing problem

I don’t know, I’m just running out of ideas. From the photos it doesn’t look like underextrusion, I assume there’s no mechanical defect that makes the extruder bob up and out (again, no evidence in the pics). All looks like wrong Live Z. Hard to remotely diagnose but maybe what looks like uneven layer is just a reflection of the filament sticking to some parts of the textured sheet better than others. I mean, it is textured, so you would expect that if you go low enough for the filament to produce a layer that sticks together that some parts are a tad thinner than others, which sort of visually disappears as you put more layers on top. At this point it just feels like you’ve tried everything but a smooth sheet, and compared to the cost of the printer $35 seems like a reasonable investment to get it to work. I can get Prusa deliver to the US in two days, so you should be able to get your hands on a sheet in Europe easily.

RE: I need your help! - Tricky printing problem

Some other handy info.

https://help.prusa3d.com/en/article/flexible-steel-sheets_2195   info on steel sheets and their use..

https://blog.prusaprinters.org/how-to-print-on-a-powder-coated-sheet_30178/   printing on the powder coated sheet

You can purchase the original PEI springsheet fro  Prusa Estore, not sure what shipping would be

https://shop.prusa3d.com/en/i3-accessories-mk3s-mk25s-etc/216-spring-steel-sheet-smooth-pei.html

There are also pros and cons of the textured sheet here on the store page for it.

https://shop.prusa3d.com/en/i3-accessories-mk3s-mk25s-etc/214-powder-coated-spring-steel-sheet.html

RE: I need your help! - Tricky printing problem

@fuchsr

Is the prusa Smooth sheet viable ( https://shop.prusa3d.com/en/i3-accessories-mk3s-mk25s-etc/216-spring-steel-sheet-smooth-pei.html#_ga=2.243627077.1592914963.1614678393-314240848.1605024621) or is the earilier one feutured on amazon better. It would be much appreciated if you recommend a sheet on amazon.se or amazon.de, as they are the available providers in my location!

RE: I need your help! - Tricky printing problem

I had adhesion issues with the textured sheet (with PETG). The sheet was new and i cleaned it with IPA before each print, but the issue did not go away (and the first layer seemed good). So i started searching for a solution and found some people suggesting cleaning the sheet with some soapy water. So i dit that and the prints sticked mutch better. So apart from the strange layer issues, this might be worth a try.

RE: I need your help! - Tricky printing problem

@tentacle1

Thanks for the advice, but in my search for a solution I came across cleaning the bed with soapy water, and it sadly didn't work.

RE: I need your help! - Tricky printing problem

I checked the Amazon stores in Sweden and Germany and while the German one has the BCZAMD sheet for the Mini, it does not carry the one for the Mk3S. 

But the Prusa smooth sheet you linked to is excellent, especially with PLA. It’s the one I use if I need a superflat surface, eg. to put two parts together. For PETG and other filaments you’ll need to apply some glue stick (not for better adhesion, but the opposite: as a separating agent, as PETG will stick too well). The smooth sheet will at least take the PLA/texture issues out of the picture.

RE: I need your help! - Tricky printing problem

@fuchsr

Try I will! And thank you for the time and help you have given me, it really means alot!

RE: I need your help! - Tricky printing problem

Keep us posted on how it works out for you! I also think getting live Z right is easier on the smooth sheet as the surface is more even and won’t create optical artifacts. In general, my impression is that folks tend not to go low enough.

Between cleaning the plate thoroughly with hot soapy water and IPA and getting live Z right, that deals with most adhesion issues. And if I think back to my pre-Prusa days, it all pales against the pain inflicted on me trying to level the beds on my old printers manually… 😇

RE: I need your help! - Tricky printing problem

@fuchsr

Now I have used the new PEI sheet for the past couple of weeks, and this is the result. The sheet helped a little bit with the printing problem where I could produce some prints. I think this is due to the more consistent printing area. The issue is that the problem still remains and largely affect the print quality. My theory is that the printer sometimes doesn't extrude filament which in turn causes these artifacts. Here are some additional pictures demonstrating the  problem. The first photo is a part of the print where filament is missing and I'm 100% sure this is not due to a hotend jam. The other pictures show weird "blobs" which tend to pop up during my prints and this is two of them. 

Thanks yet again for your patience / Ludvig