Such thing as filament being too smooth?



  • Is there such thing as pla filament being too smooth and slippery for the extruder to push through a Bowden setup?

    I got a new roll of pla and it's very smooth and has a slippery feel to it. Last two prints during the first layer after mid way it starts to under extrude so I I pause and extrude some filament and resume. An older roll seems fine, same gcode. Same brand different colors. Probably layer height is too low not enough plastic exiting causing jam.

    I can diagnose most problems but just wondering if there is such thing as filament being too glossy and slippery?



  • What is your extruder?



  • @misterj Not in my opinion. There was a time a couple of years ago when all metal hot ends started to appear and people didn't understand the reasons why the filament was swelling and sticking in the heat break area due to heat creep, that applying oil to the filament would help. It's an urban myth that still persists but for a time, it was thought to improve things. So on that basis, I'd say that there is no evidence to suggest that PLA can be too slippery.



  • the extruder gear presses the tooth into the filament to get grip.
    the spring of the extruder provides the tension for this to happen.

    if the extruder was not pushing through filament you would see grinding on the pla.

    try adjusting the spring and increasing the tension.



  • @phaedrux said in Such thing as filament being too smooth?:

    What is your extruder?

    I used the B2D extruder from thingiverse.

    https://www.thingiverse.com/thing:2289203



  • @deckingman said in Such thing as filament being too smooth?:

    @misterj Not in my opinion. There was a time a couple of years ago when all metal hot ends started to appear and people didn't understand the reasons why the filament was swelling and sticking in the heat break area due to heat creep, that applying oil to the filament would help. It's an urban myth that still persists but for a time, it was thought to improve things. So on that basis, I'd say that there is no evidence to suggest that PLA can be too slippery.

    That's true, I used to do the oiling thing too.



  • @veti said in Such thing as filament being too smooth?:

    the extruder gear presses the tooth into the filament to get grip.
    the spring of the extruder provides the tension for this to happen.

    if the extruder was not pushing through filament you would see grinding on the pla.

    try adjusting the spring and increasing the tension.

    I have dual drive gears so it's got a lot of tension on the filament. I do see some grinding sometimes too, I think its jamming somewhere by the hot end side.



  • its also possible that the other filament requires higher temperature to print.



  • @misterj With dual drive gears sometimes too much tension could lead to problems. I'd check whether you have adequate cooling on the heatbreak and whether both drive gears are actually aligned.


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