TRY THIS! Glasses Case

TRY THIS!

Design and construct a case for glasses or sunglasses that meets the following requirements:

  1. When the case is closed, the glasses do not fall out, even if the case is shaken.
  2. The inside of the case does not scratch the lenses.
  3. The case protects the glasses inside from damage if dropped from a height of 5 feet.

An optional requirement would be to include a feature that allows it to be attached to a locker, key hook, or bag strap. You also want your case to be attractive and to showcase your creativity.

What You'll Need

  • A pair of glasses
  • Material to construct your case
  • Measuring tape (for testing) 

Check the bottom of the page for materials that you might consider.

WARNING!

Prescription eyeglasses and some sunglasses are expensive. If at all possible, use an old or inexpensive pair of glasses for construction and testing. That way you don't accidentally damage a favorite or essential pair while you're working on your design. 

Eyeglass Cases

Material - A Critical Design Choice

A critical step in any design project is the selection of materials to use in assembling the final product.

Materials are sometimes specified in the requirements. For example, in the build a bridge challenge, designers are only allowed to use toothpicks and mini marshmallows. However, designers usually have to make some choices – even when a material is specified. In the paper airplane challenge, the designer has to use paper to create her glider, but she must decide what kind of paper to use.

Engineers and designers consider several factors before selecting a material to use in any given project. Some of these factors include:

Cost
Budget is always an important consideration in any project.

Physical properties
Properties like weight, texture, and color will affect to look and feel of a product and are important considerations.

Mechanical properties
Sometimes called attributes, these are specific qualities that determine how a material responds to different forces. Tensile strength, ductility, plasticity, shear strength, and friction coefficient are just a few of examples mechanical qualities that a designer may consider.

Environmental considerations
Products made of just one material – or made of materials that are easy to separate – may be more attractive for single-use items. This makes the product easier to recycle. Some materials require a lot of energy or toxic chemicals in order to manufacture, which makes them less attractive choices.

These are just a few of the factors that designers can consider when choosing a material for a project.

The Challenge

For this challenge, you should design and construct a case for glasses or sunglasses that meets the following requirements:

  1. When the case is closed, the glasses must not fall out, even if shaken.
  2. The inside of the case must not scratch the lenses.
  3. The case must protect the glasses inside from damage if dropped from a height of 6 feet.
  4. The case must include a feature that allows it to be attached to a locker, key hook, or bag strap.

In order to protect expensive expensive or favorite glasses it contains, a glasses case needs to be strong and durable but also lightweight and comfortable to hold and carry.  When working on your design and selecting your materials, consider the following:

Functionality – The glasses need to be secure in the case. They shouldn't fall out if the case is shaken or knock from a desk or table. They also need to protect the lenses from dust and scratches.  Think about where users will be taking their cases. Will the case need to protect glasses from sand or other abrasive materials?

Comfort – The case should be comfortable to hold and use. You might consider what users may be doing when they are retrieving their glasses: do they need to be able to get to the glasses with only one hand?  Will the case be used mainly outdoors, in a car, at home, or in many different locations? How might that affect your material choices?

Strength and durability – Cases need to be strong enough to protect glasses if they are bumped or dropped. Some users will want a case that can withstand rougher handling.

You also want your case to be attractive.  If you are making the case for yourself, the design should reflects your personality.  If you are making the case for someone else, it should be something that suits their personality.

Supplies and materials

Polymers

A polymer is a material made of long and repeating chains of molecules. There are many different types of polymers with many different properties. Some are flexible and stretchy while others are hard and brittle. Silicone, a type of synthetic polymer, is durable, strong, lightweight, and shock-absorbing after it hardens, so it’s typically chosen as the material to construct cases for electronic devices like mobile phones. If you have a phone with a case on it, that case is probably made from silicone or another similar synthetic polymer!

Silicone, a type of synthetic polymer, is durable, strong, lightweight, and shock-absorbing after it hardens.  There are several videos online that show how to make a phone case with silicone putty. There are also a few that show how to create elegant designs with a hot glue gun. An eyeglass case could be made on the same principle.

Plastic is also a polymer.  You may be familiar with fuse beads, small cylindrical beads that can be used to create designs that are then fused together with a hot iron.  Along with making interesting designs, fuse beads can be used to create parts that can be built or molded into containers and cases.  Here's a video demonstrating how to use fuse beads to create a holder.  There are many other how-to guides available.

Plastic can also be combined with other materials. In the following video, an eyeglasses case made with plastic canvas is decorated with yarn.  Since stiff plastic has the potential to scratch lenses, the inside of the canvas is covered with felt, a type of fabric.  More on that in the next section.

 

Fabric & Yarn

Fabric is material made from woven textile fibers.  Fibers can be natural, like cotton, linen, and wool or a synthetic like polyester or rayon.  Some fabrics are a combination of natural and synthetic fibers. Because there are many different weights of fiber and many different types of weave, there are hundreds of different kinds of fabric.

Some fabics, like fleece, felt, and batting are thick and soft and provide a lot of cushion and insulation.  Others, like canvas or upholstry, are strong and tough, but can be quite rough.  Still others, like challis or batiste, are very fine and soft, but may not hold out as well with rough handling. Using layers of fabric lets you combine features. Here is a video of a sunglasses case made from layers of fabric sewn together.

Fabric can also be combined with other materials to form stiffer cases. Here is a video showing how to create a glasses case from fabric, cardboard, and craft paper.

You can also find patterns online for knitting or crocheting cases for phones, glasses, or other small items.  Knitting and crocheting are two ways to create fabric from yarn; another was is weaving. You can also find tools that help you weave string or yarn into fabric.

Paper & Wood

You are familiar with many different kinds of paper - from cardboard to tissues.  You can find many different kinds of paper around your house that could be used to create a eyeglasses case. Here's a short video of how to turn paper tubes into a glasses case.

Here's are very simple wooden eyeglasses case made from a soft wood. If you have access to woodworking tools, you can create beautiful cases from scrap pieces of wood.  An adult can help you learn how to safely use power tools often needed when working with wood.

Leather & Metal

Leather and Metal can both be used to create small cases.  They are both strong and can be formed into different shapes. Depending on the thickness you may need to find special tools and an adult to help you work with these materials.  The following video shows how to make a simple leather eyeglasses case.

 

Getting Started

With permission, use a pair of glasses or sunglasses to model your design. Take measurements and consider the places and times that the glasses will be in the case.  If working with an old or inexpensive pair of glasses, compare the size and shape with the glasses that will ultimately be stored in the case to make sure that the design with accomodate them.

Always check with a parent or gardian before you use something you find around the house in a project.

Depending on what materials you use for making your glasses case, it might be easiest to construct the phone case around the glasses or a shape representative of your glasses. This is more likely to be true if you are using some kind of polymer for your case. If you decide to construct the case around your glasses, make sure they are protected! For example, if you’re using a silicone gun or hot glue as your material, cover glasses with a few layers of plastic wrap before starting. Do not apply hot glue or silicone directly to any glasses!

Test your glasses case

Functionality
With glasses inside, shake the case. Do the glasses stay securely in the case?  Put the case in a bookbag or purse and carry it around for a day.  Do the glasses stay securely in the case?  When the glasses are removed from the case, are the lenses still clean and scratch-free (as much as the were when the went into the case)?

Comfort
How does the surface of your case feel (i.e. smooth vs. rough or jagged)? What changes could be made to your case design to improve comfort?

Strength and durability
With your glasses NOT in the case
Place the phone case flat on a table and place a textbook on top. Does the case remain intact? Drop the case from hand height of 6 feet. Does the case remain intact?

With glasses in the case
Drop the case from hand height of 6 feet. Does the case remain intact?  Are the glasses still intact? Try using the case in your locker or book bag for a few days. Does the case start chipping or cracking?  Did the feature you use to attach the case to a locker, hook, or bag hold up over that time?

If your  case doesn’t pass all of the strength and durability tests, what are some design changes that could make it stronger?

Try this next!

If you enjoyed this activity – take it a step further with more design challenges!

Using materials you have easy access to, what are some design features you can add to your case that will improve functionality or appeal to customers?

When companies design a new product, it’s common for them to send out prototypes and request feedback from customers to improve their design. Ask a friend or relative for some constructive feedback on the functionality, strength and durability, and comfort of your case. How can you implement their suggestions in another case design?

Design a case for a phone, iPad, tablet, or other electronic device.


Photo credits:
Glassess cases image by EngineerGirl

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