Strange problem on first layer
Hi guys, I have a bit strange problem I cant figure what is.
I have a larger project where I have to print arount 100 tiles and my Prusa i3 mk3s+ have been printing pretty much flawless for the 4 month since I got it. I must say I have been impressed with the printer beyond expectations. I printet a bit over 30 tiles in prusament galaxy silver pla and they all turnes out great. I dont need alot of details so all files are sliced with 0.20.
Then I took 1 ½ month break from printing tiles and insted printed other things and I have been printing pla, petg and pce without any problems. Printer have been running almost 24/7 since I got it and I have put grease on the bearings regular, and between every new print I wash the Steel Sheets with water and sulfo plus ending it with isopropyl spray. I also run the leveling measuring thing automaticaly before every print.
So now I went back to printing tiles again and im using the same files and there is a strange problem on first layer I havnt seen before on any prints at all.
I attached pictures.
My first thought was perhaps it's time to change the nozzle, cuz layer two looks just fine. But no, layer 3, 4, 5 etc looks also fine no matter the direction it's printing in.. so im puzzled what can be the problem. So it seams only to be a problem when printing longer streaches in one direction and only on layer one.
So why are other things printing fine on first layer? It is the exactly same gcode files im using as 1 ½ month ago.
Any suggestions?
Cheers,
Frank
RE: Strange problem on first layer
Hi Frank -
I’ve had something similar recently. With me it happened after I hadn’t used the printer for two weeks or so. My solution was to go through the whole cleaning and calibration cycle, including the first layer calibration, thoroughly cleaning the sheet, nozzle, etc. This helped, but I can’t say if it was any one thing in particular.
Hopefully this helps a bit. Good luck anyway!
Three thoughts:
Redo your first layer Z calibration; I don't think you need to change your nozzle but it may have worn back a little and the value drifted.
Is this old filament? Is this the first time you have used it since you left off in the autumn? If so make certain it is dry.
And slightly desperate: there is a chance you have a build up of breakdown products from your filament on the print-sheet. If the above do not help try cleaning with acetone - DON'T make a habit of this as it degrades the PEI but two or three times a year is OK.
Cheerio,
RE: Strange problem on first layer
Thanks guys for the reply 🙂
I just realized that I may posted in the wrong section. I dont think I can move it to "Assembly and first prints troubleshooting".
Anyway, I got up 03:30 and cleaned the nozzle as good as I could, and cleaned out a bit of the filament fragments from where it's pulled in. Re-tightened the screw to the idler door and was carefully not to much and not to little as I know that can affect the pulling a bit in a weird way and also cause filament fragment to grind off the filament.
Then I run everything again from scratch just to make sure everything was reset. The wizard calibration.. it takes sooooo long :-/ And after I redo z calibration and a bit with live z calibration. I think in terms of z calibration it dosn't get any better and it looks flawless.
Now it is slightly better, but I still see some filament "grains" being layed on first layer. The layer it self looks great, so I start think you are right and it may be the filament cuz those filament grains looks like what people describe as artifacts from filament having too much moist. I just never had that problem before with any prusament and I always have filament in sealed bags when not being used. But this was new roll of galaxy silver I opened. I will open a new box later tonight when this print is finished and see if that is the same.
I can understand the logic that it occur only on first layer partly cuz of the slower speed and it's printed directly onto the heated bed, but it's just strange it is only when printing in one direction.
About the cleaning of the print sheet, im positive that is not the issue. I wash them with sulfo and warm water and use an old soft hair brush with hairs to clean them good. And then dry them with two tightly woven cotton towels before spraying with isopropyl spray before drying them again. It's become a process with two print sheet always having one ready to save time 🙂
I do have to use brim on the print and gluestick on the print sheet with these larger tiles as they tend to warp up sometimes if I dont do it. Most of the death-star tiled prints are from 12 to 24 hours so I rather dont wanna take the chance not using gluestick. But usually I dont use gluestick with pla, and rarely brim on the print. Anyway, I tested without gluestick last night and that still look the same.
I will keep trouble shooting and update when I find the solution.
Cheers,
Frank
RE: Strange problem on first layer
Solved it 🙂
It turned out that the heatblock got shaken a bit lose from the hotend heatbreak, so apparently that only showed visual on the print when it run in a certan direction on first layer. The nozzle itself was ok and tight. I found out only after a new symptom started to show. Some black drops of burned pla was dropping down from the heatblock. Just a few times, but it seamed to be increasing after two prints more.
So I had to take out the hole hotend and clean and assemble those parts again. I changed the nozzly while I was at it. Then just re-leveling z axis before printing again. Pretty strait forward when knowing that you dont have the take the hole extruder apart 🙂
Now it looks almost perfect again on first layer, and all the filament "grains" are gone 🙂
The small grainy looking things on the pictures now are just the shines from the galaxy silver pla.
Happy weekend and cheers 🙂
Frank