Bungee Launch Hook Attachment for an RC Plane

This is made to hook on the Bungee Hook made by below link
https://www.thingiverse.com/thing:474752

After it's printed, get a 3mm aluminum rod/welding rod, bend to a U shape sufficiently long enough to hook on like attached pic, then tape the thread and secure with lock nut. If you can't do exactly this, just bend the rod end upwards to lock it.

I used this one a Skyhunter

Don't have 3D printer? Try below recommendation
Budget starter : https://www.banggood.com/Anet-A8-3D-Printer-DIY-