This design is tested to work with 2mm to 4.5mm diameter nylon and polyester circular cord. The force required to release the rope is around 1-2kg depending on the materials used, similar to commercially available cord stops.
This design relies on the flexibility of the material used, so PLA and fiber filed materials will probably not work. PETG, PA, or PP recommended. Print with supports.
The author marked this model as their own original creation. Imported from Thingiverse.