What’s scarier than a Jack-o'-Lantern on Halloween? How about “lantern” made out of a fake pumpkin with four eyes, movable fangs/mandibles, and legs that move about intermittently or via a PIR sensor? Marton Ariston made just such a pumpkin, which beyond an interesting mechanical structure, is painted really well in order to scare passerby, perhaps believing for an instant that it is indeed some sort of pumpkin/spider hybrid.
The project uses an Arduino for control, along with a series of eight micro servos to actuate its four eyes, mandibles, and front legs. A number of mechanical components used here are 3D-printed, including a rather clever leg joint assembly shown in the second video below.
Inside its mouth is a lighting assembly that creates either a flame or police siren effect — no one wants to go to spider-pumpkin prison. In action, the device checks for motion on the PIR sensor every 200ms, and if detected executes a random series of scary actions. If it doesn’t see anything for five minutes it also executes random actions, perhaps to lure prey waiting on the fringes of its vision to come closer.
The pumpkin is demonstrated in the clip below, with closeup shots starting around 4:00. More info, component assembly videos, and files are available in the project write-up if you’re thinking about a last-minute Halloween display!