- 6 - “jumbo” plastic straws (10 ¼” each)
- 12 - “jumbo” paper clips (2” each)
- 6 - “size 117 B” rubber bands (7” x ⅛”)
- Unwrap the straws and cut each straw to a length of 7”.
- Place two paper clips on the rubber band.
- The rubber band should pass through the larger loop-end of the paper clip.
- Insert smaller loop-ends of the paper clips into each end of the straw.
- Try not to twist the rubber band.
- Repeat for the other five straws.
- These are the six “struts” of the tetrahedron.
- Attach the end of one strut to the band of another strut.
- You might need to remove the paper clip from the strut when making the connection.
- When done correctly, there should be three “pieces” of rubber bands passing through the large loop-end of the paper clip (one from the original strut, and two from the other strut).
- Take care not to let the straw bend! Once a straw bends, a crease is formed and will make the structure weak.
- Check out the video below for help with connecting struts.
- Attach another strut to the second strut.
- Connect it the same way that you did the first one. As you connect the struts, remember to prevent the rubber bands from twisting. Also, be consistent in the way you connect the struts. Each connection should be identical!
- Remember that THREE rubber band pieces should pass through the large loop of the paper clip.
- Connect a third strut in the same way as the first two struts.
- This should form a triangle.
- Each vertex of the tetrahedron will be formed by three struts connected to make a triangle.
- Attach two more struts to the end of one of the first three struts, making a second triangle.
- Note that the first triangle and the second triangle are pointing in opposite directions.
- Slide the loops of the paper clips so that the triangles close up. This will make the rest of the build easier.
- Adjusting the size of the triangles will be used at the end of the build to change the appearance of the tetrahedron.
- Attach the sixth strut to the end of one of the original struts as pictured below.
- Remember to always connect the struts in the same way!
- Connect the strut on the upper right with the two connected struts on the upper left, forming a third small "vertex" triangle.
- This will form a large triangle in the center. This is one face of the tetrahedron.
- For the rest of the build, this face will be considered the base of the tetrahedron.
- Flip the base over and carefully connect the three loose struts to form the "peak vertex" of the tetrahedron. Again, remember to connect the struts in the same way as the previous connections. Also, try not to bend the straws!
You made a tetrahedron!
See the next steps to make it a Tensegrity Tetrahedron.
- At this point, your tetrahedron has "closed vertices".
- In step 7, you slid the paper-clip-loops to close the triangle, and you probably slid the paper-clip-loops closed as you formed the other vertices.
- Now, carefully open the peak vertex by sliding the paper-clip-loops to form an equilateral triangle at the top of the tetrahedron.
- Open the other three vertices around the base of the tetrahedron by sliding the paper-clip-loops to form equilateral triangles.