Key cutter/duplicator attachment for my mini-lathe

[olderdan]

Nice work,
As a youngster I worked briefly in a hardware store and used to cut keys on a Yale manual copier like this one.

As it worked on a plunge cut from memory a 90 deg fine mill wheel indexed from the old one it would produce a perfect new key with sharp tips from an old one even badly worn. Modern machines just copy the profile so you get a brand new worn out key, progress?.