Automatic Sling Shot

If you're tired from having to keep your sling shot pulled while aiming, this could help. Pull it, aim, and release when comfortable.
It requires a selection of screws as well as two aluminum tubes (10mm/1000mm), a 15x3mm spring, and two sets of 5mm rubber hoses, to assemble completely. Pouches can be cut from leather, stiff fabric or some other material.
Fairly easy to assemble, and can be simplified a lot - by omitting the front step, the stock and its entire assembly, the sights, etc. The F3D file should help to get the idea how it works.

Once a projectile is loaded into a pouch and the holder arms squeezed around it, the trigger should jump up and lock the holder arms in place. And release them when the trigger is pulled. There are several rollers available for different types of pouches and projectiles.

In my case, printed with an Ender 3 Pro, regular PLA with density varying between 20% and 45%, 0.8mm nozzle. Sometimes the holes, depending on many factors, need to be precisely