Robert Swinney wrote:
I've been practicing boring a MT #1 with the compound on my Sherline lathe.
The results, after 4 tries are pretty dismal to say the least.
The compound was set against a standard MT by feeling the taper and setting
it for constant drag on a piece of paper, through the length of taper. The
material is 12 L 14. Each attempt resulted in a taper alright, and one that
would lock, but there would be a lot of runout depending on how carefully I
positioned a test taper in the new socket. It appears the taper (socket) is
a loose fit on the small end. I expect the taper male to fit solidly in the
socket and be automatically aligned straight with just a tap from a plastic
hammer. Not the case. Any suggestionss - please. Is there a better way
than "feeling up" an accurate standard taper, like I'm doing. So far I
haven't tried the chalk or layout blue method of determining fit. The throw
is so short that there is only a very small window of adjustment on a MT #1.
Yup, here's how I did it, also without a taper attachment.

I had a male taper of known quality that I used as my master. I set
the compound as accurately as I could, and then cut the taper socket.
I then applied Dykem "Hi-Spot blue" dye to the male taper, and put it
in the socket with a light touch and a twisting motion. It will show
a ring of color on the taper you just cut, either that the outer end
or the inner end. That tells you where it is too tight, so you adjust
the compound angle in painfully microscopic increments, and do it again.
When you get close, take off the tool, and rig a Dremel tool or other
similar high-speed spindle to the toolpost. (OK, I cheated here, I
have a toolpost grinder, and I'm not using a Sherline, but a lathe
200 times heavier.) With a small enough grinding wheel in the spindle,
you grind the taper with the lathe spindle running slowly. This gives
a much better surface finish, and the smooth walls will grip the taper
a lot better.

Jon