Introduction: Apply One Half Scaling to Wood Tetrahedron

About: I'm an applied physicist by training(phd Yale 2006, BA Berkeley 1998, math and physics), and have done physics research in the federal government and product development in the private sector, starting two of …

Start with the wood and tied rope tetrahedron which can be made from trash or sticks as shown here in another post I did earlier. We are going to apply the 1/2 scale operation just as I did for the triangle in another post. One tetrahedron of a given length will yield two tetrahedra of 1/2 that side length.

Materials and tools:

  • saw
  • drill
  • rope
  • 1 tetrahedron

Step 1: Cut All Pieces in Half

No need to untie, just cut.

Step 2: Drill Holes in All the New Ends

as shown. You went from 6 pieces to 12, and each one needs one new hole so that's 12 holes. I use 1/4 inch holes, but adjust as needed for size of sticks.

Step 3: Cut Ties, Assemble

As shown you need to cut some new ties out of either clothes line or nylon parachute cord or some similar material. When the two product shapes are done, trim all the ends on all your knots(all are square knots). I have also attached a 3 dimensional cartoon in .stl format showing how this operation works as well as its inverse the 2x scaling that makes 4 tetrahedra into one large tetrahedron.