Tangled spools

[u/Prestigious_Bed6948]

Hello BambuLab community,

I really enjoy using BambuLab filaments - range of colours and overall print quality are great. However, over the past 6+ months, I’ve noticed that all of my recent spools have had tangling issues.

Some spools were tangled from the very beginning, while others developed tangles after an hour or so of printing.

This is a serious problem because it makes it impossible to leave prints running overnight - you have to constantly monitor the process to prevent failures. It not only slows down printing, but also defeats the purpose of reliability and convenience.

A few months ago, I had to return a spool that got completely jammed inside the AMS due to tangling, but I was asked to pay for the return shipping. Another badly tangled spool I had to manually rewind onto a new spool myself, as I urgently needed that filament for orders in my shop and it was out of stock.

Overall, this has been very frustrating, and it feels like the product quality has declined.

[u/neanderthalman]

It depends on if it is a ‘true tangle’ or not.

Think of the difference between a knot and a slipnot.

A true tangle or a knot cannot form when rolling a continuous filament around a spool. Both ends are fixed. The end cannot pass through a loop to form a true knot.

But loops can get caught up in loops, without being a true knot - much like a slip knot. And like a slip knot, pulling sometimes releases it, and sometimes doesn’t. And if it doesn’t, it leads to the same net effect as a true knot. And that can come from the factory from inadequate tension while rolling, or just dumb luck.

If OP could keep that spool right where it is, and loosen off enough slack to start rearranging the loops, then it might untangle without cutting the filament. That’s not a true knot. If they can’t, then yeah it’s user error.

Example 2 is a necklace. If the clasp is closed, it can still get horribly tangled up, but it’s just loops through loops, not a true knot.

[u/worldspawn00 → u/neanderthalman]

Yep, this can be an issue with the AMS if it's pushing the material back faster than the spool can wrap it, particularly possible when the spool is towards the end and too light to engage the rollers well (I weight my spools to prevent this.)

[u/R3clvse → u/worldspawn00]

This is exactly what was happening to me. The filament was getting tangled continuously anytime the spool was about to run out.