Lathe: How to hold the work?

rock6.3 · #1 06-13-2012, 08:45 AM

I need to hold a 5" long piece of 1" round stock in a 3 jaw chuck so I can turn a tapered (and radiused) sided, flat bottom shape 2.4" wide into the side of the work.

I need some pointers on how to hold the work so the jaws are out of the way of the turning, and the work remains solid and centered.

The work cannot be drilled.

Ironman · #2 06-13-2012, 10:18 AM

Quote:

Originally Posted by rock6.3

I need to hold a 5" long piece of 1" round stock in a 3 jaw chuck so I can turn a tapered (and radiused) sided, flat bottom shape 2.4" wide into the side of the work.

I need some pointers on how to hold the work so the jaws are out of the way of the turning, and the work remains solid and centered.

The work cannot be drilled.

Is it too hard a steel to drill center points in the ends?

Would this tapered radiused flat bottomed shape be best done in a mill?

This sounds like a metering valve spool.

rock6.3 · #3 06-13-2012, 10:24 AM

Round stock is just cold rolled steel, easily center drilled for the ends.

Project could possibly be done in the mill but would require cutting the end radiuses by tilting the head and using a fly cutter with a 2.4" radius (which I don't have).

To visualize the project: Tapered clay flower pot + 1" round stock twice as long as the bottom of the pot is wide. Center edge of the 1" rod needs to fit the bottom of the pot when cut 1/2" deep.
Needs to fit the flat bottom, tapered side, and the radius of the side taper also.

Ironman · #4 06-13-2012, 04:25 PM

My feeling is that you should use a center drill on both ends, and run it between centers, with a faceplate and a lathe dog to drive it.
When you have completed the radius on the tailstock end, just flip it over and put it back between centers to do the other end.

rock6.3 · #5 06-13-2012, 06:44 PM

I ended up considering two methods:

1. Bolt it to a faceplate on the lathe. Problem: Lot's of hardware protruding...
2. Bolt it to a rotary table on the mill, set the rotary table on a sine plate or block to achieve the taper.

In the end I opted to bolt it to the rotary table without the sine plate, and instead took the end cut in steps to achieve the taper. This was a bit more labor intensive (rotary table is manual, not power feed) but got the job done safely.