Recreating a Classic NYC Hot Dog with a Robot

The idea

For this year's YouTube Makers Secret Santa event, where makers from around the site gift each other specialized and fun homemade devices, Becky Stern decided to bring NYC street food to Colin Furze. Because Furze lives in England, she wanted to provide him with the quintessential food, sounds, and some of the more pleasant smells that can be found on the New York City streets, namely a hot dog from a sidewalk hot dog cart. She also wanted her machine to not only dispense the dog, but place the toppings over it as well.

Recording some audio

The first part of her project involved waking the streets of NYC with a recording device and picking up authentic city audio. Some of these samples included honking, chatter, and street performers, all gathered from different locations within Manhattan.

Components and wiring

Next, Stern gathered the electronic components that would be required in order to make her machine possible. An Arduino Uno was selected to control both the three servo motors through a PCA9685 driver board, and an Adafruit Sound Board that plays the previously-recorded sound samples. Her small hot dog stand also features an LED matrix driven by an Adafruit Pro Trinket that scrolls text across its surface. The matrix and PCA9685 each communicate with their host devices over I2C, while sounds are triggered by setting a single digital pin high with the Arduino Uno.

Dispensing the toppings

One of the most challenging aspects of this project was getting the toppings to dispense reliably and somewhat cleanly on top of the hot dog below without making a huge mess. Mustard is dropped from above by using a servo motor to constrict the bottle while a secondary servo shakes the bottom of the container for a loose zigzag pattern. A set of rollers then transport the hot dog further along to the "onion sauce plopper" that, just as the name implies, drops a healthy amount of onion sauce from its vessel.

A few more decorations

To really bring on the authenticity, Stern crafted a pair of yellow and blue umbrellas by stitching fabric and then adhered vinyl lettering along the edges to denote the cart's name. She even made some polymer clay pretzels that get displayed to the side, although they unfortunately were not included in the machine that got shipped to Furze.

Tasting the results

After all of her hard work, the miniature NYC hot dog stand was working and ready for some use. As seen near the end of Furze's video, he opens up the cart from does some light assembly to put it all together. Passing a blank hot dog yielded a perfectly decorated canvas filled with splatters of ketchup and onions, albeit with a tiny mess left behind, almost identical to the authentic NYC experience.