6. Students Will Design and Produce a Push Rod Holster and Clamp

Bike Clamp and Push Holster

NGSS Standards
MS.Forces and Interactions
HS.Forces and Interactions
MS-PS3-2 Energy

Standards for Mathematical Practice
CCSS.MATH.PRACTICE.MP1: Make sense of problems and persevere in solving them.
CCSS.MATH.PRACTICE.MP2: Reason abstractly and quantitatively.
CCSS.MATH.PRACTICE.MP3: Construct viable arguments and critique the reasoning of others.
CCSS.MATH.PRACTICE.MP4: Model with mathematics.
CCSS.MATH.PRACTICE.MP5: Use appropriate tools strategically.
CCSS.MATH.PRACTICE.MP6: Attend to precision.
CCSS.MATH.PRACTICE.MP7: Look for and make use of structure.

Learning Objectives

• Students will design and produce a push rod holster and clamp to assist with the maneuvering of a child’s tricycle.
• Students will apply their knowledge of forces to create a product that assists an adult with pushing a child’s bike without straining beyond reasonable expectations.
• Students will market their product to a specific audience using any form of advertisement.

Recommendations
Group Size: 3 to 4 students, depending on how many variations you would like students to compare within the class setting. For a smaller class, groups of 2 would be ideal.

Class Size: up to 36 students

Materials Required

• At least one computer per group, loaded with Google SketchUp
• Paper and pencil for drafting
• Airwolf 3D Printer
• A tricycle, one of the most important pieces of the entire project. Asking around the campus should yield at least willing teacher. If not, there are often used tricycles for sale on Craigslist or at the local Goodwill Store within most areas.
• A broomstick (or comparable rod that can be used to test the products)

Download the free models here:
Bike Part – Clamp (SketchUp File)
Bike Pusher – Broomstick (STL)
Bike Push Part 2 – Spacer (SketchUp File)
Bike Pusher Piece – Broom End (STL)
Broomstick (SketchUp File)
Broomstick (STL)

Introduction
Assumptions being made:

• Students have a good understanding of 3D modeling. Prior to incorporating this lesson into a unit, it is recommended that students have had training on Google SketchUp.
• Students have a good understanding of SAE (Imperial) and/or Metric units.
• Students have a good understanding of formulas for Force.
• Depending on the level of the students and intricacy of the project, Kinetic/Potential Energy as well as torque may be useful to apply.

To begin the lesson, pose the students with the challenge of creating a product that will support parents all around the world. Many parents will go out and purchase a tricycle for their toddler, only to spend the majority of the time bending over to provide the force necessary to move the bike along. This presents inherent risks to the adult’s back and legs. Polling the class to determine who has younger siblings or relatives that would be in a category of riding a tricycle would make this project more meaningful for them.

Next, present students with their challenge:

Create a product that will save the adult’s back while still pushing their child in the tricycle. This product needs to be safe, secure, and capable of changing angles and swiveling along the x and y axis.

This is not an incredible difficult product to create, but it will be important to note that the product needs to be easy to use, safe, and comfortable while the child is riding the tricycle. As the challenge is being posed, show students this image for better reference. Hopefully there is someone on campus that will lend a tricycle for the sake of the project.

Give students time to work in their small groups to design potential schematics for how this might look and the reasons for their particular design. In what way will the force be distributed? How much force is necessary to move the child along with a given angle? What are the dimensions of the bike and the location of where they are going to apply the clamp?

Depending on the level of the students, tier the questions to challenge them and apply the knowledge that they have gained leading up to the project.

After each group has come up with some brainstorm ideas, have them sketch their thoughts onto a piece of paper. Visualization of a unique product is a difficult chore, so this step is essential. Within a certain timeframe set by the instructor, students will need to commit to one specific design and work collectively to optimize its chances for success.

The Meat
On paper, students will work in groups to design a unique product that they have described and sketched. All dimensions need to be included on the draft before showing the instructor. Furthermore, all dimensions will need to be checked against the measurements of wherever they play to clamp onto the tricycle at.

Have students give a reason for their design and, more importantly, why they chose the location that they did to clamp onto. In doing so, the instructor should be able to glean a strong amount of information about the group’s knowledge of forces and motion.

After their paper draft has been approved, students will take to the 3D modeling program, such as Google Sketchup, bringing their ideas closer to reality. Have students work together to manipulate the drawing such that it is a solid figure with no holes, otherwise there will certainly be printing errors.

To ensure that everything lines up accurately, groups will check their classmates’ designs prior to showing the instructor. The instructor will need to confirm the students’ drawings as best as possible before sending it to print.

Once the design has been printed, students will clean it up and verify all measurements for accuracy. Due to the variability in the project, it may be essential to note that we are looking for any product that can adequately allow an adult to maneuver a tricycle without bending over. After printing, groups will then proceed to:

• Photograph their product for their advertisement (if it is a static ad)
• Test out their product to test for the purpose it is intended to serve
• Reflect on what went well and what they would improve on if they had a chance to print again
• Create a marketing plan to sell your product to a specific group of people or industry
• Set a desired cost for the product, including shipping, based on cost to create the product and cost of shipping (Have students go shopping for reference)

For the advertisement, students have the option of their medium. Whether it is creating a website, video commercial, radio commercial, magazine ad, billboard, or many others, the key is to be creative in the area that the students are comfortable. During this portion of the project, students will need to work efficiently within a deadline provided by the instructor.

Following the creation, students will showcase their advertisement with the class.

Discussion
What were some of the challenges in designing the clamp? The lever (if applicable)? Any additional pieces?

What did you learn during the project?

Did your product break? If so, at how much force did it meet its limit?

If not, could you have used less filament to create the product? How much money would that have saved?

Just like in a Research and Design lab for major companies, the feedback and reflection on these projects will be the best part. Give students an opportunity to talk within their group and amongst their classmates to seek advice on improvements or modifications to obtain the ideal design without compromising the uniqueness.

Desired Outcomes
A desired outcome is a clamp and lever system that would allow a parent to comfortably (and safely) push around a child in the tricycle. Beyond this, it is up to the students to determine what outcome would be most suitable.

Some Possible Extensions/Modifications
To limit the amount of time spent printing, limit students to a certain filament length or mass (in grams). Both of these items can be seen in Matter Control once the gcode is generated.

To bring this down a level, provide students with the task of simply pushing the bike from a standing position, without the need to swivel on any given axis.

Once You’re Finished
Once finished with the project, have students give their product to someone who will use it on campus or within the community. Whether it is finding a parent on campus with a tricycle or a community member, the outreach will be crucial. Finding a local parents’ club or second-hand childrens’ toy store and donating the products to them would be a great gesture.