Halloween Jack-in-the-box
Building a pneumatic jump-scare prop that finally brought my childhood Halloween dreams to life.
Halloween is my favorite holiday for two reasons: it lands right after my birthday, and it gives me a free pass to engineer delightfully spooky surprises. Junior year finally gave me the resources to create the prop I had always wanted—a jack-in-the-box that bursts to life and rattles nerves.
I explored two paths for animating the prop: precise, torque-heavy wiper motors, or pneumatics that deliver raw speed. I chose pneumatics for that instant jump-scare energy, even though it meant working around compressor hookups, piston stroke limits, and mounting headaches. After breaking three custom joints and wrestling with rope rigs, I landed on a zip-tie linkage that could survive repeated scares.
By linking the jack to the lid, a single piston now launches the entire effect. Reinforcing the chassis, routing pneumatics through the base, and tuning the timing transformed a plywood box into a living spectacle.
