Importance of neatly wound filament?  

RE: Importance of neatly wound filament? - one of the filament photos

Apparently it's possible to attach only one photo.  So here's one of the photos showing the poorly wound filament.

Bob

RE: Importance of neatly wound filament?

That picture of the filament roll looks like you have a crossover knot in the filament.  The part that is feeding off the spool should never appear to be under a future loop (although just looking at the picture can be a bit deceiving since at least in principle the crossing loop could cross back on the reverse side - but it doesn't look like that here).  Most likely the spool wasn't badly wound to start with (since the quality of the wind looks good otherwise) but rather that you let go of the free end of the filament at some point after you opened the roll.  When you do that the top few coils usually relax and when you re-grab the end, unbeknownst to you it has slid under a later loop.  Then after that it will stay knotted and when you start feeding it off the roll it will at best add a ton of friction and at worst actually stop feeding entirely.  Never let go of the free end of a spool of filament!  And if you do, make sure it is no knotted when you regrab it.  To fix, carefully unwind a few loops of filament from the spool until the remaining filament is laying flat and no knot is visible.  Then keeping the cut end under tension re-roll the free filament onto the spool.  Then as I said - never let go of that free end.  When off the printer make sure it is anchored to the spool (those small holes in the spool sides work for that.

By the way, I have had lots of spools that look very messy (often from cheaper suppliers) and those are actually fine.  The vendor will seldom create a knot themselves, and certainly not anywhere but right near the free end of the filament, because you can't create a knot until the filament has a cut end (i.e., not while on the winding machine).  So don't confuse messy with knotted.  Messy works just fine, knotted does not.

RE: Importance of neatly wound filament?

If the filament is wound by machine, it's almost impossible to get a knot or kink.

However, it's very easy to mishandle filament and then blame a knot or kink on the factory.  😉

RE: Importance of neatly wound filament?

@jsw

I beg to disagree; when I first got my MK3 I was advised to use Rigid Ink because their filament was higher tolerance than most. I maintain to this day that their product was about the best I've used, although the varying softness of their PLA had me tightening and loosening off the extruder tension spring every colour. However; their spooling sucked! It looked like an analogue spooling machine, as opposed to the clearly digital winders of e.g. Prusa etc. I had a jam within ten revolutions of a brand new spool of white, and I'd never let the tension slip. (I even have a photo somewhere, but that'll be going back a few years.)

So, yeh - crap spooler, crap filament spool.

I find this very hard to believe with a Prusa supplied spool though!!! So I agree - it sounds like the filament unwound itself when it was accidentally released.

RE: Importance of neatly wound filament?

I'm sure that in a production line environment, with everybody urged to keep things moving quickly, the step of finishing off a spool, as in cutting the filament and anchoring it in the side holes, is manual.  Yes, I can envision a worker losing grip on the bitter end (with the last several turns partially unwinding) and simply grabbing it where it is instead of being sure that there were no knots or kinks.

RE: Importance of neatly wound filament?

I'd expect a poorly packed spool to be easy to spot on opening the package. If it appears spooled and taped properly, the odds of machine spooling tying a knot mid-spool are pretty unlikely, to say the least.

RE: Importance of neatly wound filament?

@bobstro

Although this is true, I have gotten a few rolls where the filament stuck to itself.  I wonder how it was stored.  Maybe a connex that was heated by the sun.  

RE: Importance of neatly wound filament?

A jsw said, entangled filament is only possible within the first few loops of filament. Just remove the first ten or so loops at once and rewind them - problem solved. It is impossible for such an entanglement to happen mid spool. Regardless of the machine you use to make the spool. Think about it, you would have to let go of the end to produce such an entanglement - but during production (mid spool) there is no end to let go...

RE: Importance of neatly wound filament?

Thanks to all of you who responded.  There have been no knots.  The crossovers have been compensated for within a few inches.  But still often seem to provide enough resistance to mess up a print.  I'll have to confess that I did not appreciate the importance of maintaining tension.  I will be a lot more careful in the future.  Thanks again!

Bob 

RE: Importance of neatly wound filament?

@bobg

Good information.  From my experience, any knots are self induced.