5 years ago
I have a machining question for the group. I have acquired a nice bori
ng head for a lathe tail stock. It has a smooth adjustment motion with a b
ig dial calibrated in mils and it would be a really nice accessory for my 1
952 Montgomery Ward / Logan 200 10" lathe.
However, the integral shaft of the head is 3/4" in diameter and will not
fit the Morse #2 taper of my tail stock. So, what can I do about it?
I was thinking I should cut a Morse taper into the shaft. There is plen
ty of diameter and length to do that, and it would allow for quick swap-out
s when I need it. I read through "How to Run a Lathe" and browsed the vari
ous ways to cut a taper:
A) turn the compound to the desired angle and cut at an angle.
B) Offset the tail stock and hold the part between centers. Cut straight.
C) Use a taper attachment.
I don't have a taper attachment, so C) is out. B) seems a little iffy a
nd I'd need to grind down a center to clear parts of the dovetail integrate
d into the head. Also I don't trust how securely the part can be held at t
he necessary offset to get the taper.
So, A) seems to be the best option. I can set the angle to better than
a degree by putting a micrometer on my compound and running it along the si
de of a known good MT2 taper held in the lathe chuck. ...actually, I just
calculated, if I get the compound parallel to the desired taper by 0.5 mils
over a 2" length, that's within 0.15 degrees of the correct angle.
QUESTION 1: How accurate does this angle have to be to have a good Mor
se taper? How smooth does the cut have to be? What are the pitfalls to c
utting a taper by rotating the compound?
And it appears that my boring head shaft is soft enough to scratch with
a hard steel cutting tool, so...
QUESTION 2: Do I have to grind the taper or can I cut it with a carbide
tipped turning tool?
I've never cut a taper before, and I need to get this one right to make
sure I don't screw up my boring head, so advice would be appreciated!