I bought quite a good pen sander but it was made for 7mm, so I copied it and made a couple larger ones for different size pens.
Had a brain fart one day and thought, I have a collet chuck,transfer punches and a metal lathe.
Turned this up on my lathe,

Cut some sand paper to size, double sided sticky tape on the back.

Used like this, what ever pen you make there is a tranfer punch to suit.
