Suppose you have just bought a nice roll of PLA or PETG filament. Then you may assume that it has been neatly wound onto the spool. Certainly with brands like Fiberlogy and our own Fill 3D filament. This filament has been produced to the highest quality standard. Just occasionally we get word that a knot, or a snarl, or in fancy English a tangle, has got into the filament. People often wrongly think that it was wound incorrectly at the factory, but in by far the most cases a tangle creeps in while the roll is being used, without you noticing. 

Before you know it your filament is in a tangle

It can happen to the best of us: while changing your roll of filament you knock against the spool holder just wrong and the roll of filament falls out of your hands onto the floor. If you were not holding the end of the roll, it falls to the floor along with it and the roll unwinds a little. This is where it goes wrong: without you noticing, the end of the spool has crept underneath an adjacent strand. At first sight nothing is the matter, but the moment you start a long print and head off to work, the filament pulls itself tighter and tighter, until after an hour it is so taut that there is no more movement to be had in the filament roll. At that moment the roll cannot unwind any further and the extruder gears will completely chew up your filament. Result: half a print, because the nozzle no longer had any filament supply and has been printing air. What a waste!

Now you might be thinking: I have never dropped a roll. Bravo! But... your filament can also get tangled very quickly when you take your filament out of the printer, for example, and then let go of it. The filament seemingly springs back onto the roll easily. But those ends are sneaky little devils. Without you seeing it, it may already have crept underneath its neighbour. Et voilà, problem!

No loose ends

Here follows the most important rule for the end of your filament. This is going to save you — hold on tight: the end of your filament may be in 3 places. Namely:

  • - In the hotend of your printer
  • - Fastened to the edge of your filament spool
  • - In your hand

Ta-daa! That was it. It sounds so simple, but this is going to prevent the tangle. Put briefly: when you open or replace a roll of filament on your 3D printer, it is always in one of the three places mentioned above. So no loose ends.

Oh dear, a tangle after all. Now what?

Sooner or later you really will have to deal with one: a tangle. The solution for a roll of filament with a tangle in it is quite simple. If the tangle is such that it has deformed the filament, then simply cut it off the roll, but in other cases you are best off repairing it. Pull a handful of windings up to just past the tangle over the edge of your spool. Here you may let go of the filament. Then wind the filament back onto the roll very carefully and let the filament be guided through your thumb and index finger. Beware of greasy and dirty hands, this does not benefit the quality. I always use a microfibre cloth between my fingers to remedy this. Do take care not to break your filament: always give it room to turn in the right direction while winding. Should you have to repair a much larger stretch, you can rewind the roll onto an empty spool. 

Forewarned is forearmed. Treat your roll with care and do not let those ends slip away any more! :) I hope you find these tips useful! Now all you have to do is make up your mind about what your next colour will be!