And The Name of the Dance is the Filament Twist

Please Login to Comment

Something unexpected happened this morning when I checked on a print this morning.
We use Colorfabb 2.2kg rolls of PETG filament. They're very big. I designed a set of spool rolling cradles that are meant to sit wide and low to accommodate the size and heft of the spool https://www.thingiverse.com/thing:2277971 For the most part, they work. However, once in a great while and normally toward the end of the spool, the whole thing will just leap out of the roller, almost catapulting itself across the desk. As I said, this normally happens toward the end of the roll, when there's less weight to it but more tension in the spool.
This morning, though, the spool in question had more than half its content on it, yet it was like someone had thrown it. I was ready to bust some heads, thinking some yahoo had knocked it over. That's when I saw a total hairpin-style kink in the filament, stuck in the receiving end of the feed tube and throwing a total wrench in the works.

Here's the problem:

I think the way I've got the feed tube and the filament cradle positioned is somehow creating twists and adding tension to the filament. I've moved the spool and done away with the feed tube. Anyone else have an idea what may have gone wrong?

Colorfabb 2.2kg Spool Roller