Ball Sander

This instructable is for a simple ball sander used for sanding inside deep turned work on a lathe, which is much safer than putting your fingers in.

I have assumed knowledge of woodturning tools.

WARNING: I am bilingual in my use of measurements so expect mm and inches

Materials and Tools

1x bouncy/rubber ball about 30mm diameter

A length of M8 threaded rod about 40cm long

2 x M8 nuts

1x small piece of timber (1 3/4" x 3")

Epoxy glue

A square of the hook side of Velcro (enough to cover the ball)

A lathe and tools

A file and vice

Scissors

8mm bit and something to use it in

Velcro backed sand paper

1. Take the piece of wood and mark the centres on each end.
2. Drill a 8mm hole through the wood blank. I had to drill from both ends ,if you do to take care to line the hole up carefully. (My screw chuck requires a 8mm hole to mount to it and this is also the hole size needed to pass the threaded rod through)
3. Mount the blank on the screw chuck, I have also mounted a sacrificial disc in front of the chuck to save my tools from hitting the chuck.
4. Turn a cove into the end the same contour as the rubber ball.
5. Turn down the sides to a taper ensuring the thin end is still a little larger than the M8 nuts
6. Sand and part off

1. Carefully drill a 8mm hole about 10mm deep into the ball (only use light pressure when drilling)
2. Epoxy the rod into the ball and clamp until dry
3. Using epoxy, glue the Velcro to the ball covering it as best as possible (its a bit fiddly)

1. Put the collar and nuts onto the rod (important to remember this as they will not go on afterwards)
2. File about 40mm of threads off the bottom of the rod to help the drill chuck jaws hold when using the sander in a drill

1. Cut a square of sandpaper and cut a square out of each corner so you are left with a rough cross shape.
2. Wrap the ball and secure all the ends with the collar and lock in place with the nuts.
3. The sander in now ready for use either in your hand or slowly in a drill

Note: Always sand on a low speed lathe settings and rest the bar on the tool rest for support.