YoYo Bros Blog Deliverable 2
1. Description of Yo-Yo Design
Our group will be designing and manufacturing a Poké Ball yo-yo, inspired by the Pokémon television show. The object from the show is a hand-held spherical container--red on the top, and white on the bottom--and a button on one side which opens the Poké Ball.
Our design is divided into two halves; the front of the yo-yo features the Poké Ball button along with a red top and white bottom (divided by a black line), and the back of the yo-yo features just the red top and white bottom, divided by a black line.
The design has five unique injection-molded pieces. The black bases will serve to hold all other components together, and will connect at the center shaft of the yo-yo; they will each have significant draft in order to improve yo-yo performance. The two bases will be identical. On the front side of the yo-yo, the red and white sections will be identical, and will have a half-hemispherical shape with a semicircular section cut out to leave room for the button. On the back side, the red and white sections will be identical and half-hemispherical in shape. A black half-ring on the back side will hold the back pieces together, and a black half-ring with a circle (to hold the button) at its midpoint will hold the front pieces together. The pieces will be snap-fitted together.
The button on the front of the yo-yo will be thermoformed, and will be press fitted into the black half-ring piece.
A weighted ring will also be placed in each of the black bases to improve yo-yo performance.
Below are our images of our design from Solidworks:
Manufacturing breakdown:
- The two external halves that make up the exterior of the yo-yo will be made by injection molding. The front side (with the button) is different from the backside (no button)
- The black curved parts that make up the interior of the yo-yo will be made by injection molding.
- The black horizontal strip on the back is injection molded.
- The black strip on the front (different from the back) is injection molded.
- The button on the one side of the pokeball is made by thermoforming.
While designing our yo-yo, we considered several principles of design for manufacturing, including:
- Simplicity
- Draft angles
- Tolerances
- Even cooling
- Thin walls
- Surface finish
In our design process, we decided to choose the pokeball design over some of our other more complicated ideas because we wanted to ensure that we could manufacture a yo-yo that was good quality but also creative and interesting.
2. Table of Specifications
Component
|
Target Value
|
Expected Tolerances (+/- 3 standard devs)
|
How we will measure
|
Diameter
|
63.5 mm
|
+0.00/- 0.13 mm
|
Caliper
|
Mass
|
.054 kg
|
+/- 0.0027 kg (+/- 5%)
|
Scale
|
String Gap
|
1.9 mm
|
+/- 0.13 mm
|
Caliper
|
Max rotational speed
|
1300 rpm
|
+/- 260 rpm (+/- 20%)
|
Laser Tachometer
|
Width (perpendicular to string)
|
65.4 mm
|
+/- 0.13 mm
|
Caliper
|
Button: top outer diameter
|
10.73 mm
|
+/- 0.13 mm
|
Caliper
|
Button: bottom outer diameter
|
15.24 mm
|
+/- 0.13 mm
|
Caliper
|
Center ring width
|
5.08 mm
|
+/- 0.13 mm
|
Caliper
|
3. Gantt Chart
Please use this link for a more detailed gantt chart:
https://www.dropbox.com/s/ksrbs3he1m353lg/YoYoBrosProject.pdf?dl=0
