Use a old hard drive as a sander.
Step 1: Hard Drive
Remove all the screws to reveal the inside. And then take out all the components. Leave the bottom plate on if you have one.
Step 2: Sanding Disk
Get your sandpaper and trace the platter onto the sandpaper.
Step 3: Glue and Cut
Add super glue and glue the platter to the sandpaper. After the glue dries cut out the platter with a knife.
Step 4: Finish
Put the sanding disk back on.
my hard drive needed the rw arm on to work so i left it there.
Plug in the power to start it up.