Doorman
Ben Wolsieffer
“Doorman” was a device I created as part of a team during my ENGS 21 (Introduction to Engineering) class at Dartmouth College. This device is designed to retrofit dorm deadbolt locks and allowed them to be opened with a key card or smartphone.
This project won the Thayer School of Engineering Phillip R. Jackson Award and was written about in the Dartmouth Engineer Magazine.
ENGS 21 is an introductory engineering class where students are challenged to create a product that would improve life on campus. I worked as part of a group of five students to design a system to alleviate some of the problems students have with dorm security. Many students don’t lock their doors because they don’t like carrying their keys with them or because they have lost their keys. On the other hand, almost everyone carries their phone or school issued ID card with them at all times. If these could be used to unlock dorms, students might be more likely to lock their doors, preventing incidents of theft and vandalism.
Our prototype went through a number of iterations, starting with a foam core mock-up. This version allowed us to brainstorm ways of interfacing with a deadbolt, and how various components would interact.
Foam core prototype
We then designed and built a prototype out of laser cut plywood. We used this material because it allowed us to quickly build complex designs, while using very little material.
First wooden prototype frame
Our first wood prototype made us aware of some issues with the motor and belt mountings, so we developed a second version that was successfully able to manipulate a lock.
Device mounted on testing board with breadboarded electronics
At this point, the control system consisted of an Arduino Uno, stepper motor driver and magnetic card reader mounted on a breadboard outside of the frame of the lock. We redesigned the electronics using an Arduino Pro Mini, so that they would all fit on a perfboard within the device. We also designed a thermoformed plastic case to hide and protect the internal components.
Final prototype with case on
This video shows the final prototype in use on an actual dorm door.
This video shows me discussing the project at our final presentation.