After playing with the flying night dragon (https://www.printables.com/de/model/404447-flying-night-dragon/comments/847889). We thought it would fun to release him from a slingshot. So I created this.
You can use a PTFE-tube to prevent losing the rubber.
I printed it with 0,30mm layers and 20% infill. I used supports (not in the tunnel!) and brim but its propably also good to print without supports.