How about using a Steady Rest to keep the tap on center away from the
tail stock. Fixed or 'traveling' rest.

The tap would have to be round or ground round if not.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Carl Boyd wrote:
I have had a problem on a couple of my recent projects. Both involved
1/2"-13 inside threads. Both were cut with a tap on a lathe.

My procedure was to drill the hole on the lathe, and then hold the tap in
the tailstock chuck to start threading until the tail stock chuck slipped,
then lossen and slide back the tailstock, put a tap wrench on the tap and
finish by had. Two out of three times the thread ended up significantly off
axis.

I had assumed that I would start the thread on axis with the tailstock chuck
and it would stay on axis when I finished by hand.

What is a better procedure? I have cut a few external threads, but am leary
to cut internals. I currently have no tools to cut internals threads but I
suppose I need some if that is the only way to do this.

CarlBoyd




----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.pronews.com The #1 Newsgroup Service in the World! 100,000 Newsgroups
---= - Total Privacy via Encryption =---