1. Ship the Chip Sort It Out Pulleys and Force
TISP: Uruguay 9–10 May 2009
User Handout Day 1
Ship the Chip Sort It Out Pulleys and Force
Christopher Lester
Yvonne Pelham
Moshe Kam
D.G. Gorham

2. Package design and the engineering behind shipping products safely
Exercise 1:
Ship The Chip
Package design and the engineering behind shipping products safely

3. Ship the Chip
The Challenge
Design a package that will securely hold a potato chip and protect it from breaking when dropped
Construct the lightest package to get the highest score
Overall score based on:
Weight of the package
Volume of the package
Intactness Score

4. Ship the Chip Procedure Sketch a design on the worksheet
Label your worksheet with Table # and Team Name
Construct a model of your package
At a test station, drop the package from a height of 1.5 meters
Open your package and examine the chip
Calculate and record your score
Using a second kit, redesign and construct a new package
Record the second design on the worksheet
Label your package with Table # and Team Name
Submit your worksheet and package to the Test Team for overnight testing

5. Ship the Chip Materials Cardboard – 22 cm x 28 cm 10 Craft sticks
6 Cotton Balls
String – 91 cm
Plastic wrap – 1 sheet of 22 cm x 28 cm
10 Toothpicks
Foil – 1 sheet of 22 cm x 28 cm
Paper – 1 sheet of 22 cm x 28 cm
1 Mailing label
1 Potato Chip

6. Ship the Chip Tools and Accessories Scissors Marking pen Pencils/Pens
Calculator
Rulers
Clear Adhesive Tape
Digital Scale
Masking Tape

7. Ship the Chip Scoring Intactness score : 100: like new, perfect
50 : slightly damaged; cracked but still in one piece
25 : broken in pieces
5 : broken in 6-20 pieces
1 : broken into more than 20 pieces; crumbled

8. Ship the Chip Calculating Volume
We will imbed the package in the smallest-volume rectangular prism that contains it
We will calculate the volume of the prism;
Width x Length x Height
For example : 3cm x 4cm x12cm =144 cm3 in the prism shown below
If your package weighed 100g and had a volume of 800 cm3 and the chip has arrived broken in 3 pieces:

9. The engineering behind industrial sorting processes
Exercise 2:
Sort It Out!
The engineering behind industrial sorting processes

10. Sort It Out Your Turn Groups of 2
You are a team of engineers hired by a bank to develop a machine to sort coins that are brought in by customers.
Must mechanically sort mixed coins into separate containers.
In our experiment we use washers:
½ Inch
1 Inch
1¼ Inch
1½ Inch

11. Distance from correct bin here, Derror = 2 bins
Sort It Out
Your Turn
How good is it?
1: “Distance” performance index:
A washer that does not get sorted has maximum Derror = 3
½in
1in
1¼in
1½in 1 1¼ 1½ 1 1¼ 1 1¼ 1½ 1 1 1¼ 1¼ 1 1½ 1 1½
Distance from correct bin here, Derror = 2 bins

12. Sort It Out Your Turn 5% How good is it?
2: “Percentage” performance index:
½in
1in
1¼in
1½in 1 1¼ 1 1½ 1 1¼ 1¼ 1½ 1 1 1¼ 1¼ 1 1½ 1 1½
# of washers incorrectly identified
Total # of washers to sort 40 5%

13. Sort It Out
Your Turn
Design (draw) a mechanical sorter that can separate the ½in, 1in, 1¼in, 1½in washers
Input: either
Parallel – all washers are inserted at start of your sorter together; or
Serial – washers are inserted at start of your sorter one at a time
Output: Each size of washer in its own physical container
Materials:
glue, tape, paper or plastic plates, cardboard, scissors or hole punch, foil, paper, cardboard tubes
washers

14. Sort It Out
Your Turn
At your table, choose 2 groups to build a parallel sorter; the other 2 groups will build a serial sorter
You will have 45 seconds to allow your sorter to operate
Predict the value of the two performance indices for your design
Construct your sorting mechanism
Test it!
Can you do better?

15. All about force and how pulleys can help reduce it
Exercise 3:
Pulleys & Force
All about force and how pulleys can help reduce it

16. Pulleys & Force Basics of Pulleys: Two orientations Fixed Pulley
Movable Pulley

17. Pulleys & Force Mechanical Advantage
Mechanical Advantage (MA) is the factor by which a mechanism multiplies the force or torque put into it.
Ideal MA:
Actual MA:
This movable pulley system has a mechanical advantage of 2

18. Pulleys & Force
Work
Work is the amount of energy transferred by a force acting through a distance
Work = Force x Distance Work = Force x Distance
A bigger mechanical advantage decreases the force required, but increases the distance over which it must be applied
The total amount of work required to move the load stays the same

19. Pulleys & Force Efficiency
The ratio between Actual and Ideal mechanical advantage is Efficiency
Frictionless system = 100% Efficiency

20. Pulleys & Force Measuring Tension Spring Scale
Calibrate: Hold spring scale at eye-level and turn adjustment screw until the internal indicator is precisely aligned with the top zero line
Measure: Create a loop in the end of the rope you want to measure tension in; attach spring scale to loop. Hold the spring scale steady and read off the tension measurement.

21. Pulleys & Force Your Turn Groups of 2
Develop 2 systems to lift a filled soda bottle 10cm with
1 pulley
2 pulleys
Build your systems
Measure the distance the soda bottle moves and compare it to the distance you had to pull
What is the actual mechanical advantage?
Measure the force you must exert on the string and compare it to the force that is finally transmitted to the soda bottle
What is the ideal mechanical advantage?
Calculate the efficiency of each system

22. Pulleys & Force Your Turn Now join with one other group at your table
Develop 2 different systems to lift a filled soda bottle 10cm with all 4 pulleys
Build both systems
What are their actual mechanical advantages? Ideal?
Which one has a better efficiency? Why do think that is?