Hyperbolic Paraboloid from Parabolic Cross Sections

The graceful surface of a hyperbolic paraboloid comes across in this model. It is easy to see the two sets of parabolas that make up the curve. (The hyperbolas are harder to see!) The model flexes and can even fold flat.

Steps

1. Cut out the pattern pieces from card stock.
   
2. Cut out a narrow slot along each line. You should try to remove a narrow strip of material at each slot. If you don't, it will be harder to put the model together, the cross sections will warp and the model won't flex easily.
   
3. Slip the first two pieces from the pattern together at their middle slots.
   
4. Assemble the rest of the pieces working from the middle of the model outward.
   

Notes

• Each cross section uses the same parabola shifted up or down.
  

References

• (Cundy and Rollett 1961)