when one wants to machine a taper by moving the tailstock over, is there such a thing as a center that has a ball on it that rides in a hole on an attachment that goes into the tailstock so that you can adjust the center to be in line with the part. If so, what is it called.

Not exactly what you are describing, but a live center does this.

I thought a live center was just a dead center in a bearing, but was straight.

You take the piece you wish to machine the taper on and drill a center hole with a center drill. You then install a live center in your tailstock and kick it off center to cut the taper. Even though the axis of the live center is parallel with the machines axis, the angle of the live center will keep things aligned with the taper. The taper and the center will be concentric with the axis of the piece. If that makes sense.

Or you can buy a live center that's adjustable for offset.

Just make sure you run the workpiece between centers. There was a thread on one of these forums a while ago where the guy had one end in the tailstock center and the other end was held in a chuck. Seems to me there was a lot of tension induced there.

Jim

quote:

Originally posted by D Humbarger:
Or you can buy a live center that's adjustable for offset.

This is the answer I was looking for. thanks everyone.

Doug!! Where oh where can one find an adjustable live center? I had one but l;oaned it to a guy and it went away. Seems like I got it from Enco but they do not list it anymore. Now , when I taper the barrels, I have to use the centers in the headstock/tailstock and a lathe dog and then offset the tailstock. Any ideas?

Aloha, Mark

Hey Doug, get a small boring head with a taper shank to match your tailstock. Adapt a center and a small bearing to the boring head. This lets you offset the outboard end of the barrel without offsetting the tailstock. Works for me. Bill

You can buy them from Grand Tool Supply Or build one like Bill described.

I never like to offset my tailstock once I have it aligned. In fact, I drilled and tapped a hole for a locking bolt so that it can't move for any reason. I use an adjustable center that I built myself. That's what lathes are for - building stuff. As an alternate, go to e-bay and look around a little. At times you can buy a complete tailstock for ridiculous low prices. Use that when turning tapers.

Ray

quote:

Originally posted by D Humbarger:
You can buy them from Grand Tool Supply Or build one like Bill described.

Hmm, not even a phone number, not too bight.

Grand Tool... 1-800-922-0512

Here is one that i made. I bought the boring head from Grand Tools & made the live center to fit it. It works quite well. Just don't take heavy cuts. As you see in the photo the nose of the live center is too soft. I have to remake it from harder material.

Nice rig Doug.

Just to be clear, my comment was directed at the website, not you.

I was thinking more of a ball and socket tyupe of arrangement, sort of like your knee works or your hip works. if you take that center and put a ball on the other end of the center, and you put that ball in a socket that is attached to the taper that goes into the tailstock, then the center will actually center in the hole in the barrel but the socket will allow the offset.

22wrf,

You can bet your butt that if there were any real advantage to keeping the centers aligned with the bore it would have been done long ago. This I think is one of those cases where some one is looking for a solution to a problem that doesn't exist.

Poleax

Flying a Shuttle in outer space wasn't a problem that existed 100 years ago either, was it?

22WRF thats a interesting idea. A center in 60 degrees & extends onto a (hole/bore) fairly deeply. I don't think the radius of a ball tip where it would contact the hole/bore would give enough support. The ball diameter would need to be sized small enough to give the maximun available support to the specific bore size.
The headstock center & tailstock centers would still be turning true to two different longitutial axis's because they are parallel to each other not pointing AT each other.

A taper attachment addresses these problems & eliminates them.