When I learned that our midterms were going to be focusing on the theme of Halloween, I was working on a lab which I used the Ultrasonic Distance Sensor. Recognizing its similarity to echolocation, I initially inclined to make something that had to do with bats.
I lost an interest in coming up with a grand interaction that has to do with bats. I was at the Alamo Drafthouse cinema in Brooklyn and saw that they were screening Evil Dead 2 , which made me think of one of my favorite movie posters, the original The Evil Dead.
I thought, why don’t I make a hand shoot out of a bucket of popcorn? From there, I tried to figure out the best way to achieve that.
I figured I would place strong servo under a stand that would quickly push a hand out of a popcorn bucket when a person tried to take some popcorn.
I ordered this servo, which is marked for as having 20kg/cm with a high torque. A mistake I find I keep on making is a higher torque means something will immediately start quickly.
The majority of the first day of working on the midterm was focused of building a piston to push the arm up and down. Nick Wallace was working in the shop and supplied me with a lasercut design for a piston that he made for a project he had in the winter show last year, but even with lots of editing, it did not fit our project.
Once fully explained with how it works, I decided it was the best way to go. It reminded me of pneumatic halloween props that you would see in haunted houses. After much trial and error, I eventually went to Amitabh and asked for advice with the piston, and after explaining to him the project he suggested to use his creation: Programmable Air.
I found an installation system that is usually used for the winter/spring show that I could repurpose into a stand for the project to be installed with. I fabricated the hole for the pipe system to attach to, a hole for the syringe to be pushed up and down, and finally a place for the arduino, breadboard, programmable air, and soda bottle to be mounted.
I had originally envisioned to use an ultra sonic sensor to trigger the hand to shoot up, but once finished being built and connected, I felt that the ultrasonic was not reliable with getting a great reading. Every person that interacts with the piece is a different height, and sometimes people are too short to trigger it. It also forces the user and interaction to occur directly in front.
I went through many different iterations of switches to try and find the best one: a photo-resistor, stepping on two pieces of foil to flip a switch, dreaming of using a IR break beam sensor but not being able to get one in time.