Cardboard Ball Chair

Step 3 Setup and cut first layer

 As noted in the previous step, this layer should be made from thinner cardboard such as 1/8 inch. If you mark the turntable with circles on the inner and outer cut lines it will make setting up the first layer easier.

Place large pieces of cardboard on the jig overlapping the cut lines by at least 1". Leaving less will cause a rough or jagged cut. Stapling the first layer is best as the staples will easily tear out of the layer when the completed half-sphere is removed from the jig. 

Note: Do NOT glue this layer to the table. You want it to hold securely to the turntable, but be easy to remove. Small nails or brads will probably work too. Don't scrimp on fasteners to attach the layer to the jig. The finished half-sphere will be heavy (approx. 50 lbs.) and having it shift or become detached would be very bad. Once you glue the second layer to the first you are committed and cannot secure the first layer any more.

Although the picture shows many small pieces being used, fewer large pieces works better. Large pieces are easier to fasten and are less likely to shift.

When the first layer is secure make your cuts. The outer cut is made by loosening the lag screws holding the swing arm and moving it down until it pierces the cardboard. Lock the arm in place by re-tightening the lags. Rotate the table and the blade should cut the cardboard easily and cleanly. The inner cut is made by grasping the inner cutter arm and pulling the blade all the way around the turntable circumference.

You should be left with a clean ring of cardboard with a 4" cross-section width. See the second picture for an idea of how the cut ring should look.