Just had to share, Ive just cut my first thread. :) :) I needed to make a 5/16 x 24tpi unf bottoming tap for a blind threaded bore. it was so simple, even at 500rpm, i think my apprehesion was needed to make me concentrate fully, but a bit ott. I got a random assortment of changewheels with my harrison, of the correct tooth form, but some with the wrong bore hole in the middle, so I had to make some sleaves first, and then figure out which gears to use, as they aren a std set...
Dave
who is dead chuffed today, bored a cylinder to smack on 0.750", a crosshead guide to 0.600" and now made a tap :)