Introduction: BeanBag Chair, Truncated Icosahedron (futball / Soccer Ball Pattern)
This project started as a means to recycle styrofoam. I had been saving stryofoam for months and was trying to figure out what to do with it. I decided to break it up and use it for bean bag chair stuffing. I researched bean bag chair patterns and considered different shapes to use to form the chair. I considered some curved patterns I had found, and also using the shapes used to make baseballs or basketballs. I settled upon a futball (or soccer ball if you are from the United States) pattern. The futball shape is a truncated icosahedron. I chose to use this since I could make a few calculations and measurements and all the cuts would be straight lines. This seemed like it would be more accurate and easier than drawing, cutting and sewing curves and arcs.
This pattern consists of 20 hexagons and 12 pentagons
Step 1: Tools and Materials
- Scissers or material cutter.
- Yardstick or meter stick (I used a drywall T)
- sewing machine
- upholstry fabric - I used vinyl.
- upholstry or heavy duty thread
- a zipper
Step 2: Sizing the Material for Your Hexagons.
I didn't have a specific hexagon size to make my chair from. I chose to work in reverse and see how many hexagons I could get out of a piece of material. The material I was interested in had a width of 54 inches. I decided that making 3 hexagons across this width would be a good size. For a reference on hexagon math I used this wikipedia page ( https://en.wikipedia.org/wiki/Hexagon ). I apologize ahead of time to the rest of the world which uses metric measurements. Just substitute your appropriate measurements. I continue to use the imperial system because materials are sourced in imperial measurements and most of the tools I have use imperial gradations.
I had to determine the actual size of the hexagon. I did this by dividing the width of the material (54in) by 3.
- 18 inches is the distance from one side of the hexagon to it's parallel side.
From this distance there are a two things I needed to calculate.
- The length of a side
- L= (0.5W)/cos(30)
- L= (0.5W)/0.866
- L= (0.5 * 18 ) / 0.866
- L = 9 / 0.866
- L = 10.39 inches
- Since decimals aren't generally used in inches we need to find the nearest fraction. This can be done by refering to a chart or just guessing and doing some division.
- The length of one side is approximately 10 3/8 inches.
- This value is simply 2L
- 2 x 10.39 = 20.78 inches
- 20 13/16 inches
Next I drew a hexagon pattern on a piece of paper to calculate how much material I would need. See the image.
- The pattern I drew consisted of 5 hexagons: a row of 3 and a row of 2. I calculated that the pattern had a height of 3L where L is the length of a side.
- So to get 20 hexagons I would need 3L X 4 plus some extra because the pattern did not include the peak of the last row of hexagons. My final formula to figure out how much material I needed is
- Material length = (3L X 4)+L
Material length = 12L + L
- Material length = (12 x 10.39) + 10.39
Material length = 134.68 inches
Converted to yards. 134.68 / 36 = 3.74 yards
I rounded up the the next whole yard which is 4 yards.
Step 3: Sizing the Material for You Pentagons
Since I started with the hexagons, I already knew the size of a side for a pentagon. The pentagon side will match up to a hexagon side in the finished bean bag chair. For sizing the material for the pentagons I "winged" it and got 3.5 yards knowing I would have excess material. Since the pentagons will not form a perfect pattern due to their angles, there will be spaces between them and calculating the exact length of material needed seemed to be to monumental of a task. I wanted to sew, not do excessive math. That being said, I still needed to do calculations to draw the first pentagon to use as a template.
Step 4: Drawing the Hexagons.
Start the hexagon pattern by focusing on the first row. I used chalk and a drywall square to draw my pattern, if you have a yard or meter stick you can use that.
- Draw reference lines vertically every 18 inches(W:parallel width of hexagon) to seperate the row into 3 blocks.
- Draw a line horizontally at 2L(twice the height of a side) or 20 3/4 inches. Doing this creates 3 blocks across the bottom of the material.
- Bisect each box vertically with a line. This is a yellow line in the image. This creates 6 rectangles. You will notice an extra horizontal line in the images. I drew this without needing it, please ignore it.
- Drawing the first side of a hexagon.
- Place your ruler at one of the bisected points.
- Rotate the ruler until the length of a side(L or 10.39in) meets up with one of the vertical edges of the rectangle.
- Move the ruler slightly to compensate for the width of the chalk, then draw your line. These lines are somewhat orange in the image.
- Using a protractor, check the angle that is formed by the new line and the edge you met up with. That angle should be 120 degrees.
Step 5: Drawing and Cutting the Pentagons.
To draw your pentagons you must first do a few minor calculations. A reference to Pentagon math can be found at https://en.wikipedia.org/wiki/Pentagon. You will need to calculate the width (W), the height from the base to the top angle (H), and the height from the base to the side angle(h). These values will be found by using our known value, the length of a side. The side length of the pentagon is exactly the same as that of the hexagon. In my example it is 10.39 inches. I used 'S' to represent the side length on my written sheet so will continue that convention here. S is the same as L used for the hexagon.
- Height to peak : H = 1.539 X S
- H = 1.539 X 10.39
- H = 15.99
- H= approximately 16 inches
- W= 1.618 X 10.39
- W = 16.81 inches
- W = 16 13/16 inches
- h = 0.9511 X 10.39
- h = 9.88 inches
- h = 9 7/8 inches
- a =(W-S)/2
- a = (16.81 - 10.39 ) / 2
- a = 3.21 inches
- a = 3 7/32 inches
Now that the values are calculated you can draw the first pentagon. Refer to the image.
- Start by creating a block that is 16 13/16 inches wide(W) and 16 inches tall (H)
- On the vertical sides of the block draw a mark 9.78 inches high (h)
- On the top horizontal line make a mark at the center point.
- On the bottom line of the block measure in 3 7/32 (a) from each side and make a mark.
- Connect all the marks to make your pentagon.
- Confirm all your angles are 108 degrees
- Confirm all your side lengths are 10.39 inches
- Make adjustments as needed.
You may now repeat the process to draw more pentagons our you can cut out your pentagon to use as a template.
The 12 pentagons can be cut out now.
Step 6: Cutting Your Hexagons.
Instead of cutting every hexagon out of the hexagon grid you may cut them in groups. The yellow and red image is the template to create the bean bag chair. The image was downloaded from https://en.wikipedia.org/wiki/Truncated_icosahedron#/media/File:Truncated_icosahedron_flat-2.svg
You may cut the groups of hexagons as they appear in the image.
- 4 curved pieces made of 3 hexagons.
- 2 pieces made of 2 hexagons.
- 4 single hexagons
Although you are cutting these hexagons in groups you will still need to sew seams in them in the next step.
When all the hexagons and pentagons are cut out you should be left with piles of material like in the last image.
Step 7: Making Groups of Shapes.
After all that work you can finally get to sewing!
To sew the vinyl together you will need heavy duty needles and thread. I used denim needles, because I happened to have them, and upholstry thread.
The first thing you will need to sew is the already connected hexagons. This needs to be done so that the hexagons remain a consistant shape when everything is attached. If we leave one side without a seam, that side will be different then all the other sides with seams.
- Fold the connected hexagons along where they share a side and align them perfectly. Fold them so the front sides are facing. Create a seam 1/2 inch from the edge of the vinyl.
- Repeat this everywhere hexagons are connected together.
After seams have been created in all the attached hexagons we can begin creating the 5 'legs'. If you look at the pattern, you will see a central pentagon. Off of each side of that pentagon are a few hexagons attached to pentagons. The smallest leg has two hexagons and one pentagon. The largest leg has 6 hexagons and 4 pentagons. You will now need to create each of those legs.
- If you did your measuring and cutting carefully, all the edges of your pentagons and hexagons should be the same length.
- To create the legs, match the pentagon and hexagon pieces with their faces together so that the edges to be sewn align perfectly.
- Pin the edges together
- Create a seam 1/2 inch in from the edge of the mated shapes.
Step 8: Attach the Legs to the Central Pentagon.
Using the same method as in the previous step, attach each of the legs that you have created, to the central pentagon as shown in the template.
Step 9: Begin Closing Up the Bag.
I unfortunately did not take images of this step while I was doing it.
Once all the legs are attached to the central pentagon, confirm that your 'mess' of material matches the template.
To close the bag you will be working on the back side of the material. As you start attaching pieces together the material will go from becoming flat to becoming sphere like. I found it easiest to work in circles. By this, I mean, connect the first five hexagons that are around the central pentagon together. Proceed to connect the next stage of shapes in a ring around that. Do this until you have nearly enclosed the entire sphere. Remember that the pattern will always be a pentagon surrounded by hexagons. If two pentagons meet up or there are too many hexagons together you will need to fix something.
I chose to add the zipper in between two hexagons. You can add it at any point during sewing but do not wait until the very last connection to do it. It will be easier to attach the zipper sooner rather then later. See the next step for the zipper attachment.
Step 10: Attach the Zipper
I chose to put the zipper between two hexagons. It could go between a hexagon and a pentagon if you wish. Be sure to use a good quality zipper. It would be no fun to have this zipper fail and spill the beans all over the place! I recycled a zipper from a back pack.
- The edges where the zipper is to be attached can't be left as a cut, so you will need to create a clean edge. Fold the edge over 1/2 inch and attach it. The edge should be folded so the backside of the material is touching itself. You will see the sew line on the front of the material
- Repeat this on the other piece of material the zipper will attach to.
- As a precaution, hand sew a stop into each end of the zipper so it can not come apart. By this I mean sew across the zipper from one side of it to the other. Do this a few times at one spot so the slider can not go past this spot.
- Attach the zipper to the material. The zipper should be somewhat hidden below the folded edges of the hexagons.
Step 11: Closing Up the Sphere.
When you get to the last two pieces that need to be attached, check to make sure the zipper is open.
While still working with the sphere inside out, sew the last seam.
Reach your arm through the zipper hole and carefully invert the bag.
Step 12: Filling the Bag.
To fill your bag you can use a variety of materials. I used a variety of stryofoam packing material and containers. Besides foam you can also add in batting or even pieces of memory foam if you have it. Be sure to use pieces of material that are a small enough size. A piece of styrofoam that has not been made small enough will prove uncomfortable to sit on. Also do not use materials that will stay compressed once you sit on them.
If you have dogs and you decide to recycle foam food containers be very certain the containers have been thoroughly cleaned. Any food residue or smell could invite your animal to ruin the bag.
Filling the bag may take some time. One thing that I found helped is to create a concave area with the zipper hole at the bottom. When you pull out on the sides of the bag this creates a suction that will draw material into the hole. Likewise do not press on the bag because this will blow material out of it.
Step 13: Sewing Calculator
I have wrote up a spreadsheet calculator that will calculate the size of your hexagons and pentagons based on the final diameter of the sphere and your seam width. I will upload it here.
Step 14: Take a Nap.
After all that calculating, drawing, cutting, sewing, and stuffing, It's time to plop down in your new bean bag chair and take a nap.