Introduction: Make a Geodesic Sphere Out of Plastic Straws

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Whether your looking for fun party or garden decorations, a way to lighten up your living/working spaces or a great way to teach geometry, this instructable will show the way!

Step 1: Gather Parts & Tools

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1/32" thick sheet of of plastic (8.5" x 11")

90 plastic drinking straws

scissors

Step 2: Cut Hubs & Straws

The attached dxf file can be used to lasercut the (12) five-pointed hubs and (20) six-pointed hubs that are needed to construct a geodesic sphere (aka a triangulated dodecahedron). The hubs should be cut out of 1/32" thick plastic (PETG or equivalent).

You can also print out the pdf version on 8-1/2" x 11 paper to use as a template for cutting them out with scissors or with utility knife on a cutting mat. This is best done by temporarily mounting the paper on your sheet of plastic with a light coat of spray mount, then peeling the paper off along with the plastic sheet's protective layer after the cutting is completed.

Pre-cut hubs are also available on Etsy:

After you've gotten the hubs ready, take 60 of the 90 straws and cut them to 85% of their original length. Set the remaining 30 full length straws aside to use in the next step.

Step 3: Assemble

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With the (30) full length straws and the (20) six-pointed hubs, assemble a basic 12 sided dodecahedron.

Each of the 12 sides will be identical pentagons.

Slide straws over every other individual hub spoke to frame pentagons using pictures as a reference.

Make sure to leave 3 alternating spokes free for each of the six-pointed hubs.

See this basic dodecahedron instructable for additional guidance. It uses 3-pointed hubs, which we will be replacex with six-pointed hubs in order to insert additional triangulation for a more spherical surface. The basic dodecahedron framework is the same in both cases.

Now with the (60) 85% length straws and the (12) five-pointed hubs, frame the inner triangulations for each of the 12 pentagon faces of the dodecahedron. See video for guidance on how to slide straws over the five-pointed hubs.

Once you have all 12 ready, begin carefully inserting each of them into the dodecahedron, face by face.

Use the available spokes from the six-pointed hubs to connect the inner triangulations to the outer dodecahedron framework.

The straws can bend but be careful not to crease them. Replace creased straws as necessary.

Step 4: Hang (Optional)

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Hang the geodesic sphere as you see fit. Fishing line and a barrel swivel are used in this photo. The sphere can also stand alone. Enjoy!

Comments

herhon (author)2017-03-02

no precut hubs found on Etsy

dantran (author)herhon2017-07-13

Hi Herhon, sorry for not keeping the Etsy post current. Please let me know if you would still like precut hubs. thanks!

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