# Engineering Projects/Igloo/Howard Community College/Fall2012/p1-502-lmra

## Problem Statement

How to prepare, design and construct an igloo in Maryland?

## Summary

Our primary goal was to figure out how to build an igloo. As a group, we attempted this by using different materials including but not limited to: Play-dough, 3D software, Sugar cubes, cork and Styrofoam. All materials experienced some success and much difficulty but the most success came from a play-dough model. A full tutorial on how to build and igloo from play-dough is located in the tutorials section. This tutorial highlights important building considerations and techniques that will be needed for a full scale model attempt. These notes will be important regardless of construction material. In addition, formulas have been derived to help calculate the angles and slopes associated with block formation. Another tutorial on "Igloo Math" outlines all the details of how the formulas were derived and an outline of their components. Finally, possible project directions have been outlined in the "Next Steps" section. A final location and construction material must still be determined including the construction of a full scale model.

## Story

### First Weekend

Videos about Igloo construction. Rank 1-5 (best to worst)

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First igloo design was created.
Igloo main body

1. Base will have a diameter of 6ft
2. Circumference will be 18.84ft or about 19ft
3. Dome height will be 8ft
4. Entrance will be 2ft long by 2ft high

Design considerations:

1. It is important that the igloo's structure has a parabolic shape and is not a hemisphere. This will prevent collapse.
2. Basic formula for dome shape is y=(-1/4)x^2+8

We searched campus for flat grassy areas with water or hose access. Most ideal location would be the Quad because of its central location, there are also suitable areas around both the East and West parking garages. Also, spent time working with GoogleSketchUp to come up with a graphical design for the igloo.

### Second Weekend

We attempted to make igloos with different construction materials and a model using 3D software.

Playdough Igloo Attempt

Igloo Attempt 1
Igloo Attempt 2

Digital Igloo Attempt

week 2
week 2
week 2

Styrofoam Igloo Attempt
We cut the Styrofoam into rectangular blocks and placed them in a circle. After determining the desired height, we used a string to find the angle we had to cut off the blocks to cause it to slope inward. Every block is held to the block next to it with a horizontal toothpick. Vertical toothpicks are used to hold the layers together where needed. Thirteen layers later, it became too difficult to add another layer, so a circular piece of Styrofoam is placed on top. Other photos of the construction process can be found here
This is what the completed igloo looked like.

Completed First Attempt Styrofoam Model

Cork Igloo Attempt
This attempt was more unsuccessful due to the difficultly in cutting block. Cork is very difficult to cut along straight lines.

Cork Igloo

### Third Weekend

Playdough Igloo Attempt
Attempt three for igloo construction was successful and produced the resulted shown below. Click here to find more detail on the construction process.

Completed with entrance
Completed igloo with entrance

The Finished Igloo in Google Sketch Up

week 3
week 3
week 3

Styrofoam Igloo Attempt
The Styrofoam cutter worked fairly well at the start. The blocks were misshapen, but precision cuts could have been made when shaping the blocks. The wire stopped heating up after the rectangular shape of the blocks were formed, but before they were shaped to fit together properly.

Hot Wire Styrofoam Cutting Tool
Styrofoam Blocks
Misshapen Blocks cut without jig

### Weekend Four

Sugar Cube
Two more attempts with sugar cubes were made using maple syrup as a bonding agent. Unfortunately these attempts were unsuccessful. You can find additional photos for attempt 1 here and attempt 2 here.

Attempt 1
Attempt 2

Igloo Math
Using Ti-Nspire CAS student software we made the images below. We also used this software to help find the appropriate formulas for our igloo and make the "Igloo Math" Tutorial found in the tutorial section.
These formulas assume an 8ft height and 7ft diameter in the base. These were our final igloo dimensions.

3D igloo shape. Elliptic Paraboloid
This is the 2D general shape for our igloo with 8 foot height and 7 foot diameter
This is the method to find layer angle for any height h.

## Material List

Playdough Igloo:
8 cups flour
8 cups warm water
4 cups salt
8 Tablespoons vegetable oil
4 Tablespoons cream of tartar (optional for improved elasticity)
Bowl, Spatula, Pot, Knife, Ruler, Dough Roller, and Flat surface
Estimated cost: \$10

Sugar Cube Igloo:
Sugar Cubes
Maple Syrup
Paper Plate
Estimated cost: \$6

Styrofoam Igloo:
Styrofoam
Styrofoam Cutter (from engineering lab)
Cardboard base
Estimated cost: \$8

Cork Igloo:
Cork Board
Knife
Estimated cost: \$8

3D Igloo:
Estimated cost: \$Free

At this point future purchases are not identified. The next team will need to determine a construction material for a full scale model and purchase it.

## Software List

Ti-Nspire CAS Student Software

36.4 Hours

## Next Steps

Math: The next team needs to find a formula that will determine block count for each layer and ideally for the whole igloo. Also, It would be best to addapt the 2D formulas to the 3D formula. This will help especially for 3D modeling. Finally. Take our formulas to the math department to see if a natural pattern can be found. Math of the Golden triangle is a good place to start.
Location: Determining where to place a full scale igloo is another task that needs to be done.
Full Scale: A construction material and logistics need to be determined for a full scale igloo.
Follow Up: It might be good to follow up with culinary department to see if they might have the means to help build and ice/artificial snow model to see what it might be like working with snow as a material.
3D CAD Model: A 3D model has been created with GoogleSketchup but it is not to scale or accurate. Ideally a CAD model would be the best to work with and give the best visuals for construction.