1 $0.73 per student

Students disassemble and analyze retractable pens. They learn how the ink pens work through "reverse engineering."

On occasion, an engineer finds an item or even designs something without fully understanding how or why it works. When this happens, it is helpful to work backwards by analyzing the finished design to see how the parts work together. Performing reverse engineering by analyzing the interactions between parts contributes to a better understanding of how something works. design disassemble pen retractable pen reverse engineering spring system How a pen works by taking it apart, analyzing its components and their functions. How different components of a system work together to reach a desired function (in this case a retractable ball point). The value of learning by disassembling products to discover how they work. Recognizing a design need (such as capped pen vs. click pen). Skills: analyzing and organizing variables to investigate how a system works, technical discussion about how the object works using new vocabulary. Other potential learning areas: compression of a spring, history of writing utensils. Obtain a supply of push button ballpoint pens, one per student (Best to get retractable "click" pens that twist apart into separate barrels so the pieces can easily fall out, so students do not have to break the casing.) Possible source: BIC Clear Click (TM) pens can be ordered from Specialty Promotions Unlimited for 73 cents each by calling 1-800-539-3751 or http://www.bicspecials.com. The Econo-Pen is cheaper (SM-103 ECONO-PEN). It is rumored that the Clear Clicks can be bought in boxes of 12, but we suspect that the design is being replaced with the barrel variety that does not unscrew. Click Pen Investigation Worksheet Click Pen Diagram Worksheet (cross-sectional diagram) Rubric for Performance Assessment assorted other pens and pencils, for comparison One of the best ways to learn about how something works is to take it apart and look at the pieces and see how they are connected. It's something we call "reverse engineering." Unfortunately, with technology getting smaller and more complex, this method becomes increasingly more difficult. One device that has managed to stand the test of time is the click pen. Let's take a closer look. Recommended Resources: Description of a ball point pen and other pens: http://www.howstuffworks.com/pen.htm Obtain a supply of twist-apart retractable "click" pens, one per student. Make copies of the two worksheets and the grading rubric. Ask some focusing questions. Before handing out the pens, have students complete the Click Pen Investigation Worksheet. Distribute copies of the Click Pen Diagram Worksheet. Discuss the two views presented. The cross-sectional view shows only the barrel and the cap, but there are many other parts in this pen. Distribute copies of the rubric. Hand out the pens and give students time to carefully disassemble their pens. Have students draw in the missing parts in the cross-sectional diagram and label them. Encourage students to explore possible ways to make the pen work/not work by removing (and modifying?) parts. Have students write in their journal. Prompts: "Choose one part of this pen and describe how it works in words and drawings." Or, "Can you make this pen simpler or cheaper by leaving out any parts? Explain in writing and drawings." Click Pen Diagram Worksheet (doc) Click Pen Diagram Worksheet (pdf) Click Pen Investigation Worksheet (doc) Click Pen Investigation Worksheet (pdf) How does this pen work? How would you describe the function of each part? What parts of the pen are essential for making the tip retractable? Is it retractable? What parts help it move in and out of the casing? What happens if you leave out a part of the system? Does the pen still work? How does this pen write? Could you refill or reuse this pen once the ink is gone? Compare this pen with another type. How are they the same or different? Which one is a better design? Why? Rubric for Performance Assessment (doc) Rubric for Performance Assessment (pdf)