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")
A square of the hook side of Velcro (enough to cover the ball)
A lathe and tools
A file and vice
8mm bit and something to use it in
Velcro backed sand paper
Step 1: Wooden Coller
- Take the piece of wood and mark the centres on each end.
- 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)
- 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.
- Turn a cove into the end the same contour as the rubber ball.
- Turn down the sides to a taper ensuring the thin end is still a little larger than the M8 nuts
- Sand and part off
Step 2: The Ball
- Carefully drill a 8mm hole about 10mm deep into the ball (only use light pressure when drilling)
- Epoxy the rod into the ball and clamp until dry
- Using epoxy, glue the Velcro to the ball covering it as best as possible (its a bit fiddly)
Step 3: The Rod
- Put the collar and nuts onto the rod (important to remember this as they will not go on afterwards)
- 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
Step 4: Finishing
- Cut a square of sandpaper and cut a square out of each corner so you are left with a rough cross shape.
- Wrap the ball and secure all the ends with the collar and lock in place with the nuts.
- 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.