Could be several things a pic would be great but if experience is any indication it could will be your glass bed (i’m assuming your still using the stock bed) the creality bed is crappy to say the least or more likely your BL touch (assuming based on the firmware its a bl touch). You could try painters tape or glue stick or magigoo but the problem will come back most likely. best fixes is to get a PEI coated sheet and replace the bl touch with a better ABL device like the EZABL.
Could also try lowering your hotend temp to around 195, 200 C
I got it to stick well when i finally slowed it down to 10mm/sec, however I think that my z-offset was incorrect and i ended up with too much “smush” on the first layer.
My guess is that means means it is time to use an adhesive to help hold the first layer in place.
The temperature of your bed is NOT the temperature you set inside the slicer. Depending on the insulation the real bed surface temperature can be 10°C lower. Just remember that the sensor usually is below the bed, while more layers of metal are between the heating element and the print surface. I usually use 65°C, which works fine with a glass print surface.
Also keep in mind that temperature needs time to spread. So pre heat the printer for around 10 minutes before start printing. Also only calibrate the printer in hot state. This combination will result in constant bed adhesion.
The print speed does not matter, when it comes to bed adhesion. PEI hates finger print residue. You can ether use alcohol to clean it or use paper glue. Some say spitting on it would improve bed adhesion.
This. If the plastic is not sticking, you are probably too far. I like DRVAX’s suggestion to look at the wipe lines and skirt lines as they go down to see if they are sticking and not too squished. The test squares help provide better visual feedback to fine tune the z-offset (and to see if the bed is warped).
You can also increase “smush” by raising “Initial Layer Line Width” in Cura (or similar in any other slicer). This makes the slicer squish some plastic between your nozzle and bed.
I’ve been using the same type of bed with decent success as low as 40° C, after wiping it with a microfiber cloth and some isopropyl alcohol. It absolutely must be heated, so giving it some time to stabilize is a good idea, and check that you don’t have the printer or slicer set to some “power saver” mode that turns the bed heat off mid print.
Getting that first layer to stick is critical, and that means tramming the bed, compensating for bed unevenness, cleaning the surface, slowing the print, making it squish, etc. The BLtouch makes a lot of these much easier, but must have correct offsets (Creality ships a lot of printers with the wrong XY offsets, requiring a firmware fix such as from Kersey Fabrications).
Teaching Tech has some very good guides in order. By your picture, I would guess the main culprit might be minuscule amounts of skin oils on the bed surface.
I just had an interesting experience yesterday. I got the best print I’ve ever had with my Ender 3 V2. I week ago I destroyed my hot end housing (the black cover that holds the fans) when a very large print failed (didn’t stick to bed) on the 2nd layer. When I woke up the next day to see my print I had a huge glob of hardened PLA everywhere. I had to destroy the housing to get it off, and had to completely disassemble the hot end to clean it. Here’s the interesting part. I decided to print my own housing (Satsana 4010) from thingiverse. I cobbled my printer together to see if I could get it to limp along enough with a damaged housing to print a new housing. The hot end fan seemed to be working correctly, but was vibrating a bit more than usual, but the part fan duct was completely gone so that fan was just blowing straight down. The print turned out AMAZING. Super smooth sides. Absolutely no sign of warping at the corners, and this part was 50mm tall.
I’m using Inland Light PLA (its the only black PLA they had at MicroCenter). My nozzle temp setting is 214, the bed temp 67. Speed was:
Infill:60, Outer Wall: 30, Inner wall: 50, Top/Bottom: 40, Initial layer: 20.
I know these are kinda slow, but I needed to get a good part out of the machine so that I could repair it with the new housing.
I did have another thought. As I was cobbling my printer back together with the damaged housing I noticed the bed belt was a bit loose. I’m not really good at doing a complete checklist before every part (shouldn’t really need to), but maybe my bed belt had stretched a bit and gotten loose, which would explain why I was experiencing degradation of print quality.
I do (now) try to wipe the bed with IPA (rubbing alcohol) before every print and I monitor the print for the first layer.
Another thing I do if I think I’m having adhesion problems is to re-check my Z offset. I have a calibration part I use that is just 5 small squares located at the corners of the bed and the center. They are only 1 layer thick. I print these, and check if there are blobs or rough surfaces, and check if the individual traces are bonded to their neighbor traces. It takes a while to get it just right, but when you do this, you will have much better reliability on that first layer.
If I ever heat my bed for pla it is to make the print unstick. I don’t have good luck with flue stick so much as I do a touch of hairspray. Not every time. Once in a while I even clean up the surface but then I must put on some spray or glue because it will never come off unless I heat the bed up to 100 c. or break it off.
I realize that I do everything ass backwards to everyone else but I work from a few years experience…and still I know nothing!