Random bad first layer lines, any ideas on cause?
I've been cranking out armor pieces for a Mandalorian & Bo katan cosplay outfit without issue when I had a print fail. The piece completed but the layer lines where not cohesive and the print ended up like a big sponge even though it completed. I removed the filament & cleaned the nozzle, cleaned the bed, tried different prints, etc but still the same issue. decided to check first layer height & when i printed the test layer I got the result in the pic. every few lines I get this random bad layer line & then it goes bad to putting down good lines. Any idea what the cause is? I've been using the same filament, Hatchbox PLA, forever.
There are some visible smears on your print sheet so first try a thorough clean, then if issues persist try a cold-pull.
Let us know how you get on.
Cheerio,
RE: Random bad first layer lines, any ideas on cause?
Thx. I always clean the bed before any big print and cleaned this several times while trying this, including with IPA. Never had any issue up to now and I’ve printed a LOT of parts this way. I’ll clean it again but I doubt this is the issue … Not familiar with a ‘cold pull’. What is that?
RE: Random bad first layer lines, any ideas on cause?
here's what it looked like after cleaning the bed again ... significantly worse actually ...?
RE: Random bad first layer lines, any ideas on cause?
well the plot thickens ... tried a different roll of filament and now the same thing happens but on a regular pattern of every 4th line ...
RE: Random bad first layer lines, any ideas on cause?
oh, that's just the 'live Z' calibration procedure. I'll try and do a recal and see if anything changes
RE: Random bad first layer lines, any ideas on cause?
So no one had any idea on what is causing this? The repeated pattern of 4 good lines, couple of bad lines then 4 good lines repeating indefinitely seems very odd ??
RE: Random bad first layer lines, any ideas on cause?
I'm with diem. Looks like some obstruction in the filament path. Did you do cold pulls as diem suggested?
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Random bad first layer lines, any ideas on cause?
Yes, the odd repeated pattern was after doing 2 more live z cals. I’ve used my needles to check the nozzle a couple of times and it seems clear. Should I try pre heating the nozzle to the highest temp or just that used for pla?
RE: Random bad first layer lines, any ideas on cause?
Live Z calibrations and cold pulls are totally unrelated and different procedures.
Cold pulls are used to clear debris from the hotend. In cold pulls you disable the steppers, heat the hotend to operating temperature, push a piece of filament into the extruder and keep pushing while you're cooling the hotend down. When you get to somewhere near 80 degrees, you rapidly pull the filament out and as it hardened while sitting in the nozzle it will pull out debris that might be clogging the hotend. See diem's link for details, or google for cold pulls or atomic pulls.
Live Z calibration is the adjustment of the nozzle height relative to the print bed surface. You can use the built-in method for first layer calibration (essentially the same thing), or print a large square or calibration strip such as https://www.prusaprinters.org/prints/105404 to get the distance right. It's called Live Z, because you can make adjustments via the LCD panel while you're watching the first layer of a model go down. What you're looking for is a continuous sheet of filament, with no gaps and no "waves".
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Random bad first layer lines, any ideas on cause?
Thx for the explanation. When I first went to the link for some reason the first layer height exlaination ve up which I am familiar with … anyway now this makes a lot more sense. I’m currently out of the country but as soon as I return I’ll do this.
RE: Random bad first layer lines, any ideas on cause?
Printer is now working correctly … had to do 2 cold pulls to clear everything but it’s functioning normal now. Thx everyone for the help!