Rubber Band Bullroarer

This is a rubber band bullroarer, modeled after the one film composer Heitor Pereira plays here to generate drone sounds.

• 2 x large rubber bands (size #107)
• 2 x 1/2" diameter dowels, 18" long
• 1 x 1/2" diameter dowel, 6" long (for handle)
• 2 x wooden ball caps with 1/2" holes
• 2 x 1x1" blocks, 6" long
• 2 x 1x1/8" shims, 5" long

1. Cut the 1x1" square block so you have two 6" lengths.
2. Mark lines 1" from either end on both 1x1" blocks.
3. On one of the blocks, mark the center on an adjacent face to where the 1" lines were drawn.
4. Take a 1/2" spade drill bit and some masking tape. Use tape on the bit to mark the depth so the bit doesn't go all the way through the 1x1" block.
5. Holding the block in a table vise, drill four 1/2" diameter holes, all 1" from the outside edges. If possible, use a drill press for perfectly straight holes.
6. Drill one 5/8" diameter hole through the center of one of the 1x1 blocks, on an adjacent face to where the half-depth holes were drilled.
7. Mark the centers of the two 1x1/8" shims, both 5" long.
8. Using a table vise, drill a 1/2" hole through the center of both shims.

1. Put the short 1/2" dowel through the 1x1 block and glue the wooden ball knobs on either end. Use a clamp or rubber bands to hold it in place while it dries.
2. Slide the shims onto the long 18" dowels. They will need to be adjustable.
3. Put the long dowels into the holes in the 1x1 blocks. Then stretch the long rubber bands over the length of the instrument to hold it all together. Gluing the long dowels into the blocks is optional since the tension of the rubber bands will hold it all together.
4. Stretch the rubber bands over the top and bottom of the shims to create a rhombus shape. Make sure the bands are all on a single plane, not twisted.
5. Spin for a drone effect.
6. Adjust the placement of the shims so the two bands generate different tones.