Diamond tipped pen mill. now I want to see that. got any close ups of the blades?
Encouraging to hear that you use gorilla glue to hold up to all the tork pressure.
do you have any dimensions for your screwdriver handles that you need to stay within? The reason I ask is that I know from experience that both hammer handle and screwdriver handle size and shape will make a big difference when it comes to hand cramps or exhaustion. Many people have experienced that, "I need a screwdriver with a bigger handle" thing. but I bought a top of the line hammer years ago. used it a lot for about 3 years. then one day went to put some trim or something in for my wife and just grabbed the hammer she keeps in the house. I noticed how tired my hand was after driving just a half dozen nails. Anyway i never have really stopped t figure out just what size handle is the best but would like to make my own turning tool handles. might as well do it right the first time.
By the way dose your pen mill want heels to go with it's diamonds?(the little wink face at the top left corner, yeah well it si supposed to be right here)