The objective of this lab is to teach students about mechanical engineering.
They will learn how to measure gear ratios, calculate gear tains, and measure gear torque. Once they learn how to do this, they will create a machine using gears and a counter to lick a Tootsie Pop. At the conclusion of the
Team member’s ______________________, __________________________
Grade Rubric How Many Licks
Design and build a machine to answer the question, “How many licks does it take to get to the center of a Tootsie Roll Pop?”
1. Identify the Problem/Product Innovation:
25 _____ Preparing a clear definition of the problem. (pg. 329 stage 1)
25 _____ Listing the constraints or limitations that the solution must meet. (pg. 329 stage 2)
2. Investigate issues related to the problem by:
20 _____ Looking in stores and catalogs to find how other people solved similar problems (competitive analysis).
30 _____ Prepare sketches or make photocopies of what you find.
3. Develop several solutions (Brainstorming) to the problem by:
20 ea 100 total_____ 5 Different Design Solutions
100 ea 500 total _____ Quality of Sketching
50 _____ Highlighting ideas that you think could be used for your final design.
4. Evaluate – Analyze Potential Solutions:
20 _____ Listing the strengths of the design.
20 _____ Listing the weakness of each design.
20 _____ Selecting the best design.
5. Make a sketch and dimensional CAD drawing of the solution you have selected for the design problem.
50 _____ Include the sketch in your design portfolio.
50 _____ Prepare a list of materials, supplies, and tools that you will need to make the selected design.
6. Implementing your design
200 _____ Build your machine and test the functionality.
If you have flaws with your design, you must return to step 4 and redesign until your machine works.
7. Evaluate your design by:
33 ea 100 total_____ Conducting the tests. 5 test runs needed.
20 _____ Describing how your machine functioned during the testing.
20 _____ Did you have to redesign? Explain in portfolio
50 _____ Summarizing the results of the test.
100 _____ Your solution fulfilled its intended purpose of 5 trials without redesign between trials. Trials must be at school and 2 of them on video.
100 _____ Your design must be safe to operate and will not spray water when in operation or leak water when sitting or in operation. You did not destroy any of the material in the box I provided for you.
100 _____ Your machine’s counter is easy to read while the machine is in operation.
100 _____ The appeal of your product is based on your selection of materials, processes, finish, color and shape. You should use color representation of Tootsie Pop material and/or paint the project except the box material supplies.
100 _____ Your product was produced with a minimal of extra money yet still is attractive in design.
Team Total Correct ________/1650
Tootsie Roll PowerPoint
Your PowerPoint must include:
25 _____ Introduction slide.
20 _____ Overview of presentation
25 _____ Identify the Problem/Product Innovation
20 _____ Investigate issues related to the problem
10 _____ Pictures of other projects like this (not to include projects from PHS)
50 _____ Take us through the design process
50 _____ 5 sketches
20 _____ 1 refined sketch
30 _____ Final drawing
50 _____ Why did you choose this design
15 _____ Pictures of your final design
20 _____ Implementing your design
50 _____ Results of your machine
30 _____ 3 or more Pictures showing your final design at work
50 _____ Evaluate your design by
20 _____ Describe how your machine functioned during the testing
20 _____ Did you have to redesign
10 _____ What went well in the process (from beginning during gear practice till the end
10 _____ What would you do differently in the future (when in a group and on your machine
20 ____ What would you do next time to improve your machine even further
10 ____ 3-5 minutes
25 ____ Slides easy to read
10 ____ Background of slides appropriate
30 ____ Each member participated equally
30 ____ Use of Props
50 ____ Presentation well rehearsed with smooth delivery that holds audience attention.
50 (25 ea) ____ Dress Professional each person
50 (25 ea) _____ Talks to the audience not the screen.
50 (25 ea) _____ Watch you body language (hands, moving back and forth)
50 (25 ea) _____ Voice (not monotone, loud enough for all to hear)
30 _____ Ready on time
20 _____ Mechanics (no spelling errors)
_______ / 950 possible
(Turn in a copy of you presentation 1 day before your presentation)
PrincetonHigh School is relatively large, urban, four-year comprehensive high school that serves approximately 2,000 students in Cincinnati, Ohio. Academic offerings include, among others, the International Baccalaureate program, technology, business, and general studies. Approximately 82% of the graduates attend college, with 60% going to four-year schools and 22% enrolling in two year/technical schools.
Before utilizing the “Tootsie Pop Challenge” in a new engineering class next year, I tested it with four engineering drafting students. It was quite successful and the students had a great time.
You are assigned the task of helping the Tootsie Roll Company to answer the age old question—how many licks does it take to get to the center of a Tootsie Roll Pop? Students can use any means available to complete the challenge, including viewing the following Tootsie Roll-related websites at www.tootsie.com/howmany-sb.htmland www.tootsie.com/memoriesLicksMachine.html
How many licks does it take to get to the center of a Tootsie Roll Pop? This was the question I posed to my engineering drafting class. None of the students had ever worked on a problem-solving activity like this. They all planned to go into engineering at the university level next year and wanted a challenging project that was not drafting-related.
The original idea came from a cooking show, but I wanted to make a lab out of it. The first step was to ask the students to do some research to determine if an answer even existed. After consulting the Tootsie Roll website, they discovered that engineering students at Purdue University had worked on the problem. They saw an example of the machine used by the Purdue students, and then began the design process working on a solution of their own.
Since my students had no experience with different engineering fields, I explained to them they would be working on the study of mechanical engineering. One of my first tasks was to teach them about gears and gear ratios. Your students may also discover the involvement of some chemical engineering. As the Tootsie Roll Pop gets smaller, you will need to figure out, “why?” If your results are anything like ours, the sugar build-up on the “tongue” material will become saturated and then the design may begin to fail, necessitating a project redesign .
For this lab, I found that we used the following standards:
The amount of preparation depends upon the labs you have. I had to gather material and machines the students will need to solve the problem. I did not want my students gathering stuff for this lab. However, if you are incorporating this into a class that involved this type of work, your students could gather materials on their own or from your classroom supplies. I used the gears from the materials provided from the Society of Automotive Engineers A World in Motion II Design Challenge 2. Other materials you will need are: materials the students can use for tongues like sponges or paper towels, scrap wood for the frame of the project, small fasteners, and, of course, plenty of Tootsie Roll Pops.
After you or your students have the materials, you must teach the design process. My students knew nothing about the design process so I introduced the problem to them and gave them the problem statement “How many licks does it take to get to the center of a Tootsie Roll Pop?” Once they understood what the problem was, they began investigating previous attempts to solve the problem. This is where they found out what other schools had done. They also found solutions to the problem on the Tootsie Roll website.
The students began to formulate their own solutions based on the materials they had to use. They began with sketches then started to rough out their solutions using the parts and the scrap wood I gave them. After inventorying the available materials, students realized they would have to refine their sketches. Once they had an idea they thought would work, they began making a prototype. This stage took the longest. None of them had ever worked with saws or drills, which meant that it was necessary for me to teach them tool safety before allowing them to work with the tools to finish their prototype.
Lastly, students tested and evaluated the product. Both groups found flaws in their designs and had to modify at least twice from what they thought would be their final design. Once they had a good working model, they tested the solution to the problem. One group found out that it took about 535 licks and the other group found out it took 1200 licks. After they did their testing I brought both groups together to see why there was such a large difference in the data. They discovered that the licking surface area of the two devices was very different. One had a large area, while the other was barely making contact with the Tootsie Roll Pop. This prompted the engineering students to try to figure out the mathematical difference in the surface area of the tongue from one group to the other. The final step was to write the lab up and discuss their findings.
The content outline is intended to organize teaching strategies to allow students to reach an intended outcome. This is the information I wanted my students to be able to do.
A. Impacts of products/systems
This is the first time I have tried this lab. The final determination of the lab design is up to each group of two students. They must look at their research and then discuss how they are going to build the lab.
The actual time to make the project and test the machine was two weeks. I had another group of students from a different class at the same time. It could probably be done in as few as five to seven days if enough dedicated time was available.
Following completion of the lab class work, students should assess their work. This assessment will be based on the successful completion of building the machine and the write up of the lab. They must include the data from at least three tests as well as their conclusion as to what process or processes made the candy disappear. They must also include an explanation of how they followed the design process and what each partner did during each part of the process. Finally there must be a summary of the process, problems encountered, and what would they do again if they had a chance to rework the process.
Pictures of previous attempts—both successful and unsuccessful.
A website about how gears work.
My students had a great time designing this project and I have taken the two machines to two different exhibits. I have had engineers see the lab and think it looks like a very fun lab to discover the concepts of mechanical engineering.
Brian Lienis a technology teacher at Princeton High School in Cincinnati, Ohio. He can be reached via email at firstname.lastname@example.org.