Final Verdict

Overall, the prototype and the competition went well. Aside from a very strange abnormality that we encountered as we were setting up for the competition, everything at the event  went much smoother than expected. The abnormality that was just mentioned was a problem with the communication between the distance sensor and the Arduino. The sensor was reading random distances that ranged from 0 to 163 inches, thus triggering the program and the machine at random times. We are not quite sure why it happened, but we especially don't know how we fixed it. All of a sudden it just decided to work perfectly. After that point, everything was smooth sailing.

During the event we had a lot of people who seemed very interested in our project, and a few that spent a lot of time talking to us about how we can take it farther. Although we did not make the finals, we were proud of how we did since we received a shocking number of votes. We had little expectations for the event, but we left feeling very good about ourselves and the final outcome of the project itself.

Below is a video of the finalized project in action

Final Team Blog Post

Final Team Blog Post


This is the part of the code that outputs the trigger pin of the distance sensor and gets the input back from the distance sensor in the echo pin.  The duration between the trigger pin and the echo pin is then changed into inches.  Th value of which is used in the following while statement to trigger the rest of the vending machine.

long duration, inches;
  pinMode(trigPin, OUTPUT);
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  pinMode(echoPin, INPUT);
  duration = pulseIn(echoPin, HIGH);

  inches = microsecondsToInches(duration);


This is the Google Drive link to all the solidworks parts as well as the assembly and the final Arduino code used.
https://drive.google.com/open?id=0B0ebIYzkcYyTVXd1WTVmdFNMUWs&authuser=0

This is one of the front faces of the vending machine.  This part was 2D cut from Opaque Acrylic.  The main cut was the door opening, while the smaller cut is the coin slit.  The other 2D laser cut parts were one of the sides and the roof, which were made out of whiteboard.


There were no 3D printed parts used in the final prototype product because we were stretched on time since we were doing the Dean's prototyping competition.  The 3D printer was also down during the time that we needed to get something 3D printed, so we had to improvise.

The bulk of the manufacturing was hand built using leftover wood parts, plywood, and metal brackets.   The hand built parts of the design were joined either with screws or with nails.  The 2D laser cutted parts were joined to the rest of the prototype with Gorilla Glue.

Week of November 23rd

This week proved to be very difficult for us. We had to have some major re-considerations after finding out that there would no mdf available. It was even more heartbreaking when we learned that acrylic would be our only material that we could laser cut. Having spent all of our $100 budget, we did not know what we should do. We ended up just cutting the front faces and the doors of the vending machine out of acrylic. We later abandoned the acrylic door idea since the acrylic was too thin. The acrylic also cracked when we screwed into it so we needed to find another way of assembling. We went back to the tool shed and made the remaining parts of the machine out of left over wood. The biggest re-design we faced this week however was the reload system. We had to 86 the system since we had conflicts with our springs and space on the top of the machine. Since we couldn't laser cut the materials that we wanted, the vending machine is not coming out as nice as we would want it to be. Another issue is the distance sensors being very inconsistent and not working at times. We have a lot of problems right now but we hope to fix them all by Thursday.

Week of November 17th

Just finished up all the solid works models for the outside layers of the machine and the dispensing door. We hope to have them laser cut by the end of this week. We also received most of our equipment: 4 servos, 2 distance sensors, and 2 battery packs. Things are looking good.

Week of November 9th

Finished construction of the framework of the vending machine. We decided to make it completely out of wood since that is what we already had in our homes. We did have to make it in a shed outside, which wasn't very fun since it was about 40 degrees. This is what it looks like.

Team Vend 2014 Members:
Vincent Giudice
Michael Gugliotti

Project Statement:
This project is to design a self-sustaining vending machine to operate in the middle of a room without the need of a wall plug.  This prototype vending machine will be coin-operated and feature two openings for faster accessibility.  This prototype will not have a refrigerator component, but could be upgraded to include one in future prototypes.

Interesting Links:

https://www.youtube.com/watch?v=YrBg0lObjro

https://www.youtube.com/watch?v=ZZmUuRG87sU