Adhesion problem with 6mm nozzle  

Eminent Member

I have found my .6mm nozzle a challenge but this is a new one - first layer adhesion.  I did all the usual things - cleaned surface (Isopropyl, also tried Dawn dish detergent), brims, and no brims, bed temps at 60 and 65, and  extruder temps of 210 and 215.  I want to use Prusament Mystic Brown and need a low temp of 210 to get the correct color.

The strange thing is I printed this with a different PLA a month ago using a brim, with no problems. The parameters I used however do not work with either Prusament Mystic Brown or with Hatchbox.  (The PLA that worked is no longer available).

Each line of the perimeter (or brim) goes on OK but the next line pulls it up a bit.  Eventually there is enough pull to create a curl and then it is all over - it gets high enough to so the extruder pulls the print off the plate.  In the pic the top Left corner are the three perimeters, and the bottom Right corner shows the diagonal infill that has pulled up the corner.  

Note that the perimeters are raggedy - that seems to be the nature of using a .6mm nozzle on the first layer but it is not an issue as the higher levels are usually very smooth and cover it up.  If you look closely you can see the left most diagonal infill line is as smooth as the perimeter lines.  They all  start that way and then the subsequent adjoining lines pull parts of them up.

Finally I also changed the Infill/Perimeters overlap from 25% to 15%, and also changed the Infill Fill Angle from 45 to 90.  Both of these helped a bit but not enough.

It is almost as if something on the R side of the extruder exerts a pull on the adjoining line.

Thank  you in advance!

Posted : 25/10/2020 11:14 pm
Illustrious Member

First guess is that filament is very wet and is boiling off the moisture as it prints, resultin gin the minor steam explosions along the way.  Do you hear any hissing or sizzling or see steam rising from the nozzle as it prints?  You can even try extruding some filament into the air - raise the extruder, use Move Axis Z to extrude when the print fan is off: listen for a hiss and sizzle and look for steam coming off the extrusion of filament. 

This post was modified 8 months ago by --
Posted : 26/10/2020 12:04 am
Eminent Member


Thanks Tim - I did not think of that because the Prusament was new - the Hatchbox PLA had been around for awhile in a bag with dessicant - but still.  In any event I am dehydrating them for three hours and will give it another shot. 



Posted : 26/10/2020 2:09 am
Prominent Member

What are you printing on? Smooth or textured sheet? That first layer looks horrible.

I've been printing with the 0.6mm nozzle around the clock for the last three days. Not once did I see anything like this. The 0.6mm nozzle prints just like the 0.4 on the smooth sheet I'm using for this. I didn't even wipe the bed down between prints 🙁 

We should exclude the obvious issues first, so I assume you are slicing with the 0.6 mm profile (I don't want to sound patronizing but I've done silly things like this myself, more than once...). In the same category of basics, make sure there's no gunk sticking on the outside of the nozzle that could pull filament off. I would also do a test print with a 0.4mm nozzle to exclude filament related issues. Then I would repeat first layer calibration. I usually don't find that necessary when switching between nozzles but who knows. And I'd try something like Layerneer to improve adhesion. Beyond that, I don't know, this looks just bad...

Posted : 26/10/2020 11:07 am

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