Thanks for your reply.
Think I could still be tempted to try it with a larger motor.
If for no other reason than apart from the motor, it would cost next to nothing to build and the motor could be transfered into a full size shredder at a later date…
How about using the blades from an office paper shredder?
Most modern paper shredders are capable of shredding CDs and credit cards.
The blades, guides and possibly even the frame from the shredded with a larger motor would make a cheap plastic shredder…
Acetone softens the polystyrene into a thick liquid.
You can pour into a mold or shape by hand.
As the acetone evaporates the material hardens.
As sourced from Google.
I used acetone when I worked with GRP, it did dry your skin out if you used it without rubber gloves.