Innovative Student Builds a Vending Machine in His Locker
What do you do with an unused locker beside holding those smelly gym clothes? One innovative student wanted to use his locker for more and made an awesome soda vending machine.
“Lockers just aren’t what they used to be. With so many schools moving to electronic devices for books, lockers become less of a space for your books, and more of a question of: “What am I going to do with this?”
What if you could use that space for your own vending machine? In this Instructable, I’ll tell you how I came up with the idea, how I designed it, how I solved a few problems along the way, and how it all turned out! So pop open a can of your favorite drink and come along!
A little less than a year ago, on the way back from lunch to U.S History class, I looked at one of the lockers and thought “how cool would it be to have a vending machine fit entirely inside of a locker?” Shortly after, I mentioned the idea to a few classmates at my table. We then talked about it for a while as a joke, but the further we went on, to me, the idea seemed entirely possible!
I began drawing up rough sketches to the side of whatever assignment we had in front of us. Before going any further, the next day, I brought a measuring tape to the school, and during lunch, I went to the locker to get every measurement I could. A few days later, school was out for the summer.”
“You can’t make a vending machine out of a Nike shoe box. Lately, I’ve been taking advantage of our school’s new Epilogue Mini 24-inch laser cutter. I decided to use black acrylic for the front face of the vending machine. It cuts nicely, and it looks pretty clean as well. After programming the control panel, each component needed a home. I had to make sure nothing ran into anything else from the back side, given that things like the coin acceptor and battery take up a substantial amount of space.
I did a quick mock-up in Photoshop before drawing the panel in CorelDRAW. This is a great time to name the machine! I liked “The Soda Locker.” I ended up liking the engraved grid look in the background with rounded rectangle borders. I cut a few holes for the button, keyhole, screen, logo displays, and coin acceptor. Then I mounted everything in its designated spot. I also put two pieces of clear acrylic to cover the logo displays.
Everything was looking great so far!”
“One of the key features the control panel had to have was theft protection. I didn’t want others removing the control panel from the locker. The front of the locker has a lip where the door rests into. I cut two boards with the same thickness as this lip and cut slots in each board which would allow for a key driven arm to be pushed into when in use. Once locked, the control panel is “too big” to be pulled out. Then all I have to do to get the control panel out is turn the key and pull forward.”
“After getting the electronic aspect out of the way, I moved on to the dispenser boxes. These would go at the very bottom of the locker. I designed a laser cut ready box on Autodesk Inventor. After laser cutting, I fit it together a few times before gluing with wood glue. They ended up being pretty strong when finished! Each box holds 6 cans of a certain type. The Boxes were mirrored images of each other, so leaving the last leg out creates a nice opening at the bottom to grab your can. The hole on the side of the box served to hold a C shaped channel that turns 90 degrees and back each time a can is sold. This prevents all cans from being dispensed, while dispensing on at a time. I added a bit of length at the bottom for the can to roll before dropping to prevent people from messing with the C channel.”
“The dispenser wouldn’t work without a C shaped channel for the cans to fall into. Before moving to 3D-printing, I made a few prototype dispenser channels. I started with cardboard wrapped around two acrylic disks with a couple of acrylic gears. While there is no mechanical advantage to gearing it 1:1, I did this to keep the dispenser low profile by mounting the servo on the inside of the box. It wasn’t perfect, but the cardboard worked pretty well. I tried replacing the cardboard with a thin sheet of heat-warped acrylic but it ended up turning out worse.
I came up with a final design in Fusion 360 and had it printed from the https://www.makexyz.com/ service. If you haven’t gone through MakeXYZ, I highly recommend it! It was fairly cheap for the quality parts I received. It’s also very quick.
In the last picture, you see a piece clamped on to the back wall of the box. I glued a few stoppers that fit into the slots of the 3D-printed piece which serve to keep the part from sliding out of the box. Once the stopper is glued, you can’t take the part out anymore.
Then I mounted the servo from the inside of the box, placed a laser cut gear on the outside, and tested it out after wiring it to the control panel.”
“Because each dispenser held only 6 cans, I needed an area to store extra stock. Conveniently, the vending machine is in a locker, made for storage! I made a panel to cover up the top half of the locker where the backpack hook is located. It consisted of a frame, a couple of hinges, and an inside panel with a key lock. Again, this kept the grid theme to match the rest of the machine.”
“The actual vending machine was entirely finished at this point! The next step was preventing the locker from ever being left open. I went to my local yard store and picked up a 15-inch tension spring. Again, the locker had another convenient feature. There was a small divot at the top of the back of the locker. I hooked the spring to this using a paper clip, bending it through several times. Then, again, thanks to another hole, I ran a bolt through the top edge of the door close to the hinge. Then it was a simple as hooking the spring to the bolt. I could have increased the tension by placing the bolt in another hole, further from the hinge, but I’m not willing to have my fingers chopped off in a door slam!”
“After securing the door with a spring, it was time to jam the combination lock open! Just like any middle-schooler with a new locker, I input the combination once, and while holding the latch open, I shoved a pencil through the back side. I also taped it in place to keep it a little more secure. Now the locker was open to anyone. Conveniently, the locker still latched when closed, requiring you to at least pull up before opening the door. If I ever need to close the Soda Locker for maintenance, I can easily pull the pencil out and the machine is locked again. Nobody will ever need to know my combo.”
“The last step? Ask your girlfriend to prom! After finishing the Soda Locker, I was so excited to show it to her. With prom around the corner, what better way to ask her than having the first buy drop a can for her to pick up asking her to prom? Pretty sure nobody’s been asked this way before!”
“After day one, the vending machine was a hit! On average, 6 cans are sold in just one passing period. Although to me, it was far more rewarding to hear “Dude, have you checked out locker 808 yet?” as students passed each other in the hallway.”