Inspired by a Stratasys sample print, I decided to re-draw and improve the desktop, micro catapult. It can throw a small bit of paper, chunks of raft, and pretty much anything you can fit inside. Selected ammunition can be thrown around 2 metres, plenty to hit unaware victims at another desk!
It's a Print-In-Place model, without the need for any support material. It also takes advantage of the material properties, meaning that there are no external parts or hardware, it's just the material that allows it to flex and store energy. I was pleasantly surprised to find that the ABS/PC I printed it in doesn't break or retain a memory from being fired over 100 times.
It's best printed in ABS at around 0.25mm resolution. Cooling of the neck can be difficult, so make sure either your cooling fans are on full or just print two at once! If you're looking for a left-handed version, it's a simple as soing a mirror (or scale by -1 in the X-axis)