Thanks Trevor, I will try to get the search terms better. Even the
exact
title did not show up.

After the plain turning is done the  the hob blank is blued and
put on the reliever and marked on the end with a cutter bit as it
turns.
The pattern screw is marked so the two parts can be put on the
reliever the
same way they were during plain turning. Both arbors have a keyway.

The mark on the hob blank looks like a circular saw. This shows
where to put the gashes. Since the beginning of the teeth are
not perfectly formed as slack is being taken up at the start, the
gashes should be as small as practical. Later the odd parts will
be cut away and the gash made wider.

The tops of the hob teeth are relieved with a straight cutter first.
I blue the hob blank to be able to see how the cutting is going.

Then the thread relieving cutter is adjusted to pick up the thread
once
and then stays in synch. Small adjustments can be made on
the pivot screws of the follower that carries the nut.

This is the first time for me on U-tube.  Charlie