Inconsistent First Layer Print
I am trying to print this:
As you can see - I can print it! Once...
When I send it to the printer a second time, this happens:
I don't understand why I can get a good print immediately followed by a failed one. I am using a steel plate (not the powder coated) and I am cleaning the plate with alcohol in between attempts.
I am also letting the bed and hotend totally cool down...not sure why that would matter but its what I am doing to get a good "reset".
I am using eSun PLA+ at 215/75 and have tried using a raft, but the quality of the side touching the raft isn't acceptable. I'd really like to print this directly on the bed for the best results.
Am I screwing up the first print settings? I can't see how since I am able to get an occasionally good print. Are the temps too high (although I have dialed them both down with the same results).
Help!!! 🙂
-Dave
Re: Inconsistent First Layer Print
The first print sort of cleans the bed, the second print works. You grab the part and bed with your hands to remove the part, next print fails.
See the part below about the streak test: your bed is showing streaks of oil like crazy.
Hot Water wash: often - as needed
Handle the bed only by the edges.
Wash the bed in hot water, use a fresh paper towel as a wash cloth, with a few drops of plain dish soap (Dawn, unscented, no anti-bacterial, etc.). Rinse well in hot water - if you have very soft water, rinse a bit longer.
Dry the bed with a fresh paper towel.
Handle the bed only by the edges.
Place bed on printer.
Alcohol rinse: every few prints
Once in a while, an alcohol rinse is helpful to remove PLA residue. It does not remove finger oils.
Pour a 5 cm puddle of 91%+ alcohol in the middle of the bed, use a fresh paper towel to scrub the bed. Wipe up all the alcohol.
Streak test: when contamination is suspected and after a wash
With a fresh piece of paper towel, and very clean fingers, dampen the towel with 91%+ alcohol, and wipe the bed side to side moving back to front, like you're painting it with alcohol. The alcohol should be thin enough on the towel it quickly evaporates. If you see any streaks, the bed is dirty and needs a wash.
Acetone wash: infrequent
Pour a 2 cm puddle of acetone on the bed, scrub it around with a fresh paper towel. It will evaporate fast as you clean. This step removes PEI oxides that form over time and with heat, and improves PLA adhesion to a like new state.
Re: Inconsistent First Layer Print
I tried cleaning with alcohol and with acetone between previous test prints with the same bad results.
The photos don't show how clean the bed was in earlier testing.
I can say I am not using NEARLY as much solvent as you mention. I also have not tried washing the bed in hot water and dish detergent.
I'll try doing a deeper cleaning and see if i can straighten this out...
-Dave
P.S. At one point I flipped the steel sheet over to print on the other side and got an immediate fail. I'll try to clean it better and see what happens.
Re: Inconsistent First Layer Print
This section of your image shows why the print is failing: all those streaks are hand oils moved around by the alcohol. A soap and hot water wash is required. Wash your hands in soap and water, rinse well; then using a paper towel wash the sheet with a few drops of dish detergent scrubbing with a paper towel - not your dish sponge; then rinse really well handling the sheet only by the edges. Dry with new fresh paper towels; and place the sheet back on the bed - again, handle only by the edges.
Alcohol, and even acetone, will not do a great job removing oils from the bed. In fact, they do a great job of moving oils from your hands to the bed and spreading it into a micro-thin layer that repels PLA. That's why I suggest a streak test.
OP opened a new version of this at https://shop.prusa3d.com/forum/how-do-i-print-this-printing-help--f63/first-layer-issue-t28792.html