RE: Any idea what causes this pilling and mess on the first layer?
@pete-b3
Good to know that adjusting the speed helped.
But as far as I'm concerned something is not correct, either with my Mini or some setting somewhere. When I first got my Mini I don't remember having this problem. ( I received my printer on Dec. 24th, 2019, so some of the first printers shipped) Along the way I had problems with the printer's assembly and quality control. The set screw on the extruder gear came off and I had to disassemble the extruder assembly and retighten the set screw. The 2 rods that hold the nozzle assembly "froze" up, and the nozzle was VERY hard to move manually on the two rods. This was only after printing about 10 hours. I had to lubricate the rods with some oil, to get it to move freely. Had the nozzle get clogged so I changed it with my preferred nozzle from E3d the Nozzle X (pricey but has been working really well on my MK3), The USB flash drive that Prusa included with the printer came apart. (the board of the flash drive came loose and pulled out of the case when I insert and remove the USB drive.) so I replaced it.....and so on..... this is the pain we have to go through as an early adopter of the Mini.
So I believe there is some other problem not discovered that is causing this problem. I'm pretty sure the speed setting are what its supposed to run at, but for whatever reason, the Mini has a problem keeping up with the speed. Even though I replaced the stock Nozzle with a new E3D nozzle I'm thinking that it may be a problem with the nozzle (again). My thinking is that the Mini cant "push" the quantity of filament required through the nozzle, but by slowing down the "speed" it has time to push the required filament through the nozzle. The first layer is printed at a slower speed by default (20mm/s), so it has no problem with the first layer, but after the first layer the speed increases and that is where it cant extrude enough material through the nozzle. I may try replacing the nozzle again to see if a new nozzle will fix the problem.
RE: Any idea what causes this pilling and mess on the first layer?
@pete-b3
Just another post to let you know what fixed my problem with inconsistent quality that you described. Yesterday I upgraded the firmware on my Mini from 4.0.3 to 4.0.4. It seemed like it was a minor fix that said it fixed the "jerk" setting, whatever that is. I figured I might as well try a small print job that ALLWAYS failed with my 4.0.3 firmware version. My first print came out as expected at full speed. I decided to make sure by reprinting it a 2nd time, and again it was as expected at full speed. So today I decided to print a different item that also messed up. It involves 10 pieces, and all 10 pieces printed as expected. (at full default speed). So for me, upgrading to the 4.0.4 firmware fixed my problem and I'm considering my issue fixed. You may want to try the upgrade, hopefully it will solve you issues.
RE: Any idea what causes this pilling and mess on the first layer?
@pete-b3
Just another post to let you know what fixed my problem with inconsistent quality that you described. Yesterday I upgraded the firmware on my Mini from 4.0.3 to 4.0.4. It seemed like it was a minor fix that said it fixed the "jerk" setting, whatever that is. I figured I might as well try a small print job that ALLWAYS failed with my 4.0.3 firmware version. My first print came out as expected at full speed. I decided to make sure by reprinting it a 2nd time, and again it was as expected at full speed. So today I decided to print a different item that also messed up. It involves 10 pieces, and all 10 pieces printed as expected. (at full default speed). So for me, upgrading to the 4.0.4 firmware fixed my problem and I'm considering my issue fixed. You may want to try the upgrade, hopefully it will solve you issues.
Thanks. I'll give that a shot. The Mini isn't the fastest printer to begin with, so slowing it down has been painful 😀
Pete
RE: Any idea what causes this pilling and mess on the first layer?
@pete-b3
Yeah, slowing down the printer IS painful, but given that the firmware update seems to have helped me, maybe Prusa knows of some issue and are trying to fix it for those of us with problems?
BTW, I forgot to add that whenever I do a firmware upgrade I also run through the "Calibration Wizard" on the printer, which tests everything and does a first layer calibration. When doing a first layer calibration I also use the default "000" settings instead of the "stored" value. Don't really know if running the Wizard also helped, but I figured it can't hurt, and who knows what really changed with a firmware update, so I redo the Wizard to "reset" everything.
RE: Any idea what causes this pilling and mess on the first layer?
read problem and solving make me feel better hope for 3d printing, i'm start my 1st print today. 🙂
RE: Any idea what causes this pilling and mess on the first layer?
@pete-b3
After I thought I "Fixed" my problem, I started having the same problems a month later, so I checked everything again, replaced the PTFE tubing, and eventually had to slow down my speed to 70% once again. I was printing at 70% with reasonable quality, but sometimes I would still have prints with quality issues. (If I slow down to 50% prints would come out pretty much as expected, but 50% was way to slow for me.) I ran across a post that mentioned a problem with the thermistor on the Mini that was reading the temperature much lower than expected. Since I was unable to figure out the problem with my mini, I figured I have nothing to lose by trying to print at a higher temperature than what I set on my MK3S (240 degrees). So I raised the temp from 240 to 250 degrees, and noticed that the quality seemed to increase. I then increased the temperature to 260 degrees and quality was really excellent at 70% speed. I then disabled my 70% speed settings and ran my prints at 100% speed, and my prints were excellent with absolutely NO problems. I have been printing for about a month at a MUCH higher temperature than my MK3S and everything has been printing perfectly for every print so far. (I'm printing with PETG and even my "stringing" has disasppeared.) So I have to assume I have the same issue as the poster who mentioned a bad thermistor that was reading the temperature incorrectly. This "higher" temperature setting means that either the thermistor is defective, or the design of the Mini causes the temperature reported back to the thermistor to be off by 20 degrees.
Just posting this as a possible thing to check for those that have exhausted all other solutions. I'm planning to order a new thermistor to try to confirm the issue, but for now I'm printing with quality that equals my MK3S, and this time I'm pretty sure I've found the real problem that was causing all the trouble in the first place.