As I promised, this is how to turn the sphere from my last post into something that will securely hold onto your towel or shop rag and easily turn it loose when you want it to.
Materials and Equipment
- 2 by 4 by 5 inch block of wood
- 1/2 inch rod or drill bit
- Drill press with movable fence
- 1 3/8 forstner bit (a spade bit ought to work as well)
- various clamps
- 5 by 1 by 3/4 inch strip of wood
- two support blocks of wood
- two 1 1/2 by #8 screws
- previously turned sphere of ~ 1 1/4 inches diameter
I made my sphere slightly less than 1 3/8 inches diameter for the purpose of having it fit loosely into a 1 3/8 inch hole. If you have a different size bit, you can make your sphere accordingly.
The fence on my drill press is 2 1/4 inches tall. By placing a 1/2 inch drill bit at the fence base and then leaning my 2 by 4 block against the drill bit and the top of the fence produces a 12° to 13° angle.
Clamp the 2 by 4 block in place such that the 1 3/8 inch hole is centered from side to side. Position the fence so that the back edge of the hole is between 1 1/8 and 1 1/4 inches from the front edge of the block. Clamp other blocks of wood to the fence, one on each side of your 2 by 4. Drill the hole to a depth of 2 1/4 inches.
Remove the 2 by 4 from the drill press, and mark a line across the top that almost reaches to the back edge of the hole and down each edge that extends down 2 1/4 inches. Mark a line across the front 2 1/4 inches down from the top. This marks the section of the 2 by 4 to remove.Place the sphere into the groove formed by the forstner bit. Lay the 5 by 1 by 3/4 inch strip of wood on top, centering it over the groove, and screw it into place. The strip of wood should be such that the sphere cannot escape. If needed, you can plane down the portion of the 2 by 4 to lower the strip of wood until it holds the sphere in place.
You are now ready to screw it to the wall. You place your towel or shop rag between the strip of wood and the sphere. A gentle tug downward makes the sphere grip the towel tighter. To remove, lift the towel up, the sphere will rise and move back away from the strip of wood and release the towel.