M&M Dispenser

M&M _CAD.png

Design Challenge

For my class, ME 102, our task was to create a custom M&M dispenser that dispenses a pile of 10 M&M’s one at a time. We were required to actuate it with a rotary movement, incorporate hardware (including a spring), and have it be operable with one hand.

Initial Sketch of

Initial Sketch of my idea

 
After sketching out different ideas, I decided to try a rotary mechanism, where three “pac-man” shaped circles would be fixed to an an axle. I chose this because I believed it could be a unique mechanism I hadn't seen before and it would be feasible to 3-D print.
The idea was that the top and bottom circles would be fixed, while the middle circle would be free to rotate. The openings would be the exact size to grab a single M&M, and as the middle circle was rotated CW to be coincident with the top opening, one candy would be dropped into  by the middle enclosure and consequently be rotated CCW to line up with the bottom hole on the right.

Prototyping Process

  • Rapid Prototype

    In order to test to see if my idea would actually work, I built a rapid prototype, using cardboard for the circles and a hot glue stick as the axle. I went to through different iterations of the three circle mechanism, which taught me that the thickness of the circles must be just big enough to grab the M&M and that the distance in between each circle couldn't be to small, or else the M&M would get stuck. In addition, I realized the importance of adding washers to limit the friction between them.

  • Functional Prototype

    After learning that my mechanism could be effective, I created a more functional mechanism by using a shoulder screw to attach the three circles. I also decided to create a lever extending from the middle circle to rotate it and attach a Spring to.

  • Final Prototype

    After 3-D printing the circles and the spring support, I built a base out of foam core and hard styrofoam, and attached the spring via shoulder screws on the lever and the support. I placed them horizontally in order to have a linear motion of the spring. Although the plan was to 3-D print the entire structure, I ended up using foam-core to build the platform due to 3-D printing issues.

M&M_Drawing.png
 

Final Video

Final Project Presentation of Design Process