I had some defunct stepper motors and was casting about Instructables.com looking for ideas when I came across this:
I also used some spares from this one:
This is a double remix!
Step 1: First, Catch Your Rotors.
I started with three motors and followed the instructions to extract the rotors.
Step 2: Choose a Center
I happened to have some spare enamelled disks left over from another project:
You can use buttons or beads. As in the the third example where I have used a shop-bought bead.
Experiment before you glue them in.
Step 3: Glue in the Center.
I used rapid epoxy resin for this step but any permenant reasonable strong adhesive will do.
Step 4: Convert to a Pendant
You can use any type of cord from your local craft shop.
Use a loop of wire to attach the cord.
For something a bit more special I have used some flat silver chain. This came from a jewellery supplier, but you could recycle some chain from an old necklace.
Step 5: Here is the Finished Product.
I have seen quite a few other things in my box of "things too useful to throw away" you could do this kind of project with. For example Heat Sinks come in all sorts of shapes and sizes.