PLA sticking to the nozzle instead of the heatbed
Hello everyone,
I'm currently struggling with starting my prints, because PLA always decides to stick to the nozzle instead of the heatbed (bastard). I have i3 MK2 for almost a year and so far I never had this issue.
So far I've tried XYZ calibration, adjusting PINDA, updating firmware, cleaning nozzle, tweaking temperatures and printing speed. I'm using the very same filament and 99.9% IPA like before.
From time to time, first layer gets laid down successfully and then everything is ok. But it involves multiple attempts, a lot of frustration, fingers crossed and praying to all the deities.
Now I'm suspicious about the heatbed. Is it possible that PEI and/or temperature sensor could degrade over time? Still, I have my printer for less than a year and I'm not printing that often.
I'm looking forward for your suggestions, tips and advices. Have a nice day 🙂
Re: PLA sticking to the nozzle instead of the heatbed
Hi Robert,
what settings do you use for first layer thickness? I use 0.20mm to 0.35mm depending on how much detail thee is in the model.
anything below 0.2mm gives me problems, For PLA, I use a bed temperature of 50C for small models, and up to 65C for large models. and I usually use 200C for the filament .
How do you clean the PEI sheet? I use 99% IPA, or acetone then IPA if changing from say TPU or PETG to PLA...
do you use several 'Skirt' outlines before starting the print proper? this can allow you to adjust the live Z to get good squish (sometimes helps if you run the first layer slower than normal, turn it down to say 50% on the LCD display
you could consider using a BRIM, to increase adhesion.
as the first layer prints,
if it lays down individual round shaped lines of filament, then your Live Z needs to be a bigger negative number to lower the live z adjustment.
if it lays down filament in a solid sheet with waves in it, the chances are your either too low with the Live z, or over extruding, try using the tune menu, and temporarily lowering your flow to say 95... restore this after the first layer...
no doubt others will have other suggestions.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: PLA sticking to the nozzle instead of the heatbed
Hello Joan, thanks for your fast reply 🙂
currently I'm using 0.2mm for the first layer, with bed temperature between 55-60°C and nozzle set to 205-215°C. Before every print, I clean the bed with 99% IPA.
Just like you said, I'm usually using at least two outlines to adjust Z, however this is already the stage where it goes wrong. Basically what happens is that even though Live Z is just right, in every sharper corner the nozzle pulls the material and thus it doesn't stick to the bed. This is the case even for slow printing.
Re: PLA sticking to the nozzle instead of the heatbed
Do you have a spare nozzle around? I would try replacing it to see if PLA stuck on your nozzle is adhering to the extrusion.
- Gab
Re: PLA sticking to the nozzle instead of the heatbed
Try a new nozzle, an e3d blue sock, or a "rub" of the PEI with the rough side of those yellow/green sponges used to wash dishes.
Re: PLA sticking to the nozzle instead of the heatbed
Try to clean the bed with Acetone.
All my adhesion problems went away since I switched to that.