PLA sticking to nozzle

I’m having trouble printing with PLA. The bed seems to be calibrated properly, but no matter how I adjust temp & z-height the PLA prefers to stick to the nozzle instead of the bed. I’ve tried painting tape instead of the Taz’s glass bed, which helps a bit, but as the nozzle runs close to already-extruded lines, it snags them and drags them along - causing a big ball of PLA to form on the tip of the nozzle. It’s happens most often when the head abruptly changes direction. Does anyone have any suggestions? Thanks.

Are you printing with blue painters tape on a hot or cold bed? PLA sticks really well to a cold blue tape covered bed. PLA will also stick to the clean PET surface of the bed when set to 50-55C. You may also want to try bare glass laid on top of the existing bed, heated to 60-70C. The part will stick to the bed until cooled to ~40C, at which point it will pop off.

I’ve had good luck printing PLA on the PET tape like Orias said. I spent some time making sure my bed was extra level and printed with the bed temp at 60C. I’ve been printing mostly ABS since it is easier to work with (I get better print quality in general with it), but I did 10-15 PLA prints on the TAZ’s PET tape without issue.

My PET tape did have a coat of the Lulzjuice/ABS glue on it. I haven’t tried printing PLA on clean PET tape, but when I tried ABS on clean tape, I got the same issue you are describing. So if you have any Lulzjuice around, you might want to give that a try just in case it helps remove a little slickness from the tape.

I’m printing white pla on bare glass, heated to 60c, cleaned with rubbing alcohol.

I had the same problem as you with the hot end at 185 and 190, raising the printing temp for the first layer to 195 did the trick, then lowered to 190 for the rest of the layers

I finally got good adhesion by lightly sanding the kapton tape with 320 grit sandpaper, cleaning it up with rubbing alcohol, and heating the nozzle to 195° for the first layer. I tried painters tape as well, and while it did stick reasonably well, the surface quality wasn’t great. Thanks for everyone’s help!

Some users have encountered flaking or delamination when removing parts when printing on bare glass. We recommend printing with either the stock PET surface, or with the new PEI print surface that some of our more advanced users are using with great success.