This is a simple clip for attaching a kite string to a kite. You can tie the kite string to this, and then switch the clip between kites.

I recommend printing in ABS at 100% infill. No supports needed. You may need to sand a bit to fit your kite's string hole.

Not flight tested yet.

Uses and includes my Bezier library.

The kite string holder that I'm using is this one.

Update: Simplified model.