Ok so I'm having an issue with the very first part of my prints

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(Kevin Danger Powers) #1

Ok so I’m having an issue with the very first part of my prints not wanting to stick to the bed right away. What happens is that everything heats up, I have it prime the nozzle so it’s ready to print. The print head moves in place and starts extruding/moving (as it should) but like the first 1/4 to 1/2 an inch of the plastic that’s laid down gets pulled up. Once I get past that part, the rest of the print goes fine unless it needs to retract and print on a different blank spot. The same thing happens. It leaves a little tail sticking up and this can cause my prints to fail. I can usually just push it down so it’s out of the way and the print will be fine but it’s really annoying. I’ve already tried screwing with the temps, bed height and extra prime amounts. The prints themselves come out great but it’s just that first little bit when it extrudes onto the build plate that is causing issues. I’m currently using an Ender 3 with PLA. Nozzle temps between 205 and 215 don’t seem to help at all. Bed temps between 45 and 70 don’t help at all. It’s like the print head isn’t waiting to move long enough after the extrusion starts and there just isn’t enough plastic coming out at the very beginning. I can take a picture after work if it helps.

(Neil Darlow) #2

Is your initial prime sufficient? I’ve noticed that Cura in particular performs a retract before commencing printing of the skirt. This can lead to a deficit of plastic at the start if your prime doesn’t put out enough surplus material.

(Kevin Danger Powers) #3

@Neil_Darlow if you’re talking about the prime before the print head touches the bed, yes. I even made it prime some extra just to make sure. It’s almost like I need an extra prime amount option for just the first layer. This just feels like a software issue, I just gotta figure out what.

(Anders Sandström) #4

I usually enable the ”skirt” option (available at least in slic3r) to make sure nozzle is primed.

(Kevin Danger Powers) #5

@Anders_Sandstrom I do as well. It will just do the same thing. The first part just doesn’t stick but once it moves just a little, it sticks just fine.

(Anders Sandström) #6

Ok, I keep the skirt ~5mm from the print, so in case it does not stick it will in anycase be a bit away from the print and not interfere

(Dale Dunn) #7

I seem to remember having that problem until I cleaned the (hot) nozzle with a brass wire brush.

(Neil Darlow) #8

Do you print the first layer slower? Your post didn’t mention this. I print the first (and last) layer at 50% of normal speed.

(Jeff Parish) #9

Does it help at all to turn off retraction just to see if that is part of the issue? Is there anything that has changed between now not initially sticking and when it used to stick just fine?

Does it help to put a small brim around the object? At least the part that does not stick will get removed and there will not be any lifting between the skirt and the desired part by triggering the peel up again.

(Kevin Danger Powers) #10

@Neil_Darlow yeah. It’s currently less than 50% actually

(Neil Darlow) #11

You mentioned bed temperatures between 40 and 70. I’m not familiar with the Ender 3 bed but for my Anycubic i3 Mega with an aluminium/glass/PrintBite+ combination I need to use 80C on the bed.

Perhaps worth increasing the bed temperature. You can always lower the temperature after the first layer.