Nice machine. Some of us Know of the family that built it.

3/4" shaft ? wow that is large. Does it screw out of the head ? Many do.

If so then buy a Morse taper for it.

If you don't have the proper equipment it would be trivial for a pro
shop to do the job. If the shaft is forever on the head (doubtful) it
is a one time shot for the head. Wrong cut - trash the head.

Martin


On 4/4/2017 4:35 PM, Daniel Koller wrote:


Hi folks,

I have a machining question for the group. I have acquired a nice boring head for a lathe tail stock. It has a smooth adjustment motion with a big dial calibrated in mils and it would be a really nice accessory for my 1952 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 plenty of diameter and length to do that, and it would allow for quick swap-outs when I need it. I read through "How to Run a Lathe" and browsed the various 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 and I'd need to grind down a center to clear parts of the dovetail integrated into the head. Also I don't trust how securely the part can be held at the 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 side 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 Morse taper? How smooth does the cut have to be? What are the pitfalls to cutting 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!

Thanks,

Dan