Wanted to make an easy print-in-place, no support friction lock for drawstrings on bags, shorts, etc that would fit 4mm paracord.

A few itterations lead me to this. It was a bit of a challenge to keep the size small but still have a good angle for solid friction yet easy opening.

Tested one to failure, and the PETG deformed at around 25kg but the friction mechanics still held until complete failure.

If it is going to go through the washing machine, it will proabably need to be PETG/ABS/Nylon, etc.

UPDATE: Scaling works from 34% to 400%. The big one is sized for 15mm climbing rope -but don't!…though I can tell you it did survive with 90kg(200lbs) and some gentle shock loading. Would be interested to see ho much it can take, but I don't really have the test rig for that.