I reworked the design by Papierschnitzel.at from Printables and instead of the printed string, which always caused me problems and was not visually appealing, I converted it to rubber band. The throwing arm is slightly different, the trigger is completely new with more safety. The bolts are more secure when cocked. There is one more bolt in the card - because they are gone very quickly in the office 😉
Works perfectly in PETG.
After breaking out, which I managed without tools, the parts have to be assembled. I have created a sequence of photos for this.

Have fun with it