Cardboard Ball Chair

Step 4 Prepare ring piece template, cut stock

At first I used different shaped pieces of cardboard but that was inefficient. To save time I made a keystone-shaped "brick" pattern out of a piece of fiber board and used that for cutting consistent cardboard pieces from the 1/2 inch stock. The time it takes to do this is well worth it.

I have a well-appointed shop so I was able to quickly prepare my pieces by cutting long 6 inch strips on a table saw. I then made the angle cuts with a radial arm saw locked to 10 degrees. These cuts could also be made with a hand held radial saw or a handsaw. Even though the 1/2 inch cardboard cuts easily with a hand saw, I'd use that as a last resort as there will be many yards of cardboard to cut.

The pattern was made when the ring was approximately 2 inches high. It is a fairly accurate 1/16 section of the circle. For the next few inches of rise the cardboard pieces fit together well with little or no gaps. However, as the layers rose and the diameter of the rings got smaller the pieces didn't fit together as well. The final piece to finish each ring was usually a partial piece that had to be hand-cut to fit the gap. This didn't turn out to be a problem because small gaps won't weaken the body of the sphere, larger gaps can be filled with scrap and a paper-mache layer will be applied to the half-sphere when the cutting is complete.

Because the angles and width of the pieces will change as the project progresses it's safer to only prepare a few rings' worth of pieces at a time. I found myself adjusting the size of my ring pieces every few rows and it saved me from having pre-cut pieces that were too narrow to have enough overlap for a clean cut.