Is there a doc, er,.. I mean machinist in the house?

[Darkchyld]

I have an Atlas model 3991 12" thread cutting lathe. 36" between centers. The tool holder seems damaged. Seeking advise and how to's.
Thanks

[skreemer]

try these guys at the tinkers guild...

http://www.network54.com/Forum/goto?forumid=9013

[Greg B]

I guess I qualify. What type of toolpost is it? If it is a rocker type, I.E., it has a round body withe a bolt at the top and a slot running vertically, throw it out and get a quick change.
If it is a turret style, I.E., usually a square body with a horizontal slot going all the way around, it's better than a rocker. But still, throw it out and get a quick change.
A quick change has a main toolpost body which mounts individual toolholders. Changing tools is as easy as turning a lever, taking one toolholder off, and replacing it with the another one. The toolholders are height adjustable, and once the height is set for a specific cutter, it stays set.
There is more than one type of quick change toolpost, but most will be either piston locking, or wedge locking. A wedge type is going to be more rigid and repeatable, but costs a little more. On a light lathe like the Atlas, a piston type will be more than up to the task.
I guarantee, once you use a quick change, you'll never want to use anything else. It will make your lathe work much more enjoyable and productive.
Greg B.

[Darkchyld]

Turrent style. You've hit right on the issue. Can't find anything for it. Maybe I'm just not looking in the right places yet. Skreemer pointed me to a site that I'll check out in detail as time permits.

I do appreciate any input!

[mike J]

www.doriantool.com <-very good stuff, not cheap, but that's what I use. Mike J

[Greg B]

Yes, Dorian is a high quality toolpost. As is Aloris and KDK. However, since it is likely that the cost of one of these with the necessary holders would cost more than the lathe, they are not, IMHO really cost effective, at least not to a HSM type of guy.
There are however, several lower priced copies, and I mean WAY lower priced. They are usually imported from either India or China. These cheaper toolpost sets are more than good enough for an Atlas 12x36.
Heck, Darkchyld, I've got a set, made in India, piston type, with a T-slot nut to fit an Atlas. If you're interested, contact me off list. My apologies if
this is frowned on.
Greg B.