Indexing symmetrical part in lathe

I am having some trouble figuring out how I can index a part in my lathe.
My machine is a HAAS ST15Y
I have a 15.5" long tube, 1.25 dia with a hex pattern on both ends.
The hex is roughly 3/4 deep (Z axis).
I need the flats of the hex patterns to be lined up with each other.
Maybe I am missing something simple, I just can't think of it.
How can I index the part in the collet chuck so the flats end up being symmetrical/parallel?

Thanks in advance.

How accurately?
A couple or a few 1000 pcs?

1) If standard +/- 0.5° I would set the part on the granite slab, up against a vertical surface. Rotate the part until you can line up a height gage with the point of the hex, or on the flat. Move the height gage to the other end and scribe a tic' mark on the OD.
G54 your C axis to line up with the tic mark. Machine your hex.

2) Machine a feature that aligns with the hex, to be removed on a subsequent opp.

3) Make an alignment sleeve/clamp (whatever you can attach to the OD, temporarily) with a flat on it. Align the hex with the flat on your sleeve, and indicate off that when setting G54 C0.

4) Make a spindle plug with a mating hex or a single flat. Install a piece of hex stock and clamp the chuck down. Indicate the flat on the hex, and set C0. Remove the hex, set your collet to hold your tube, and go to town.

That's all I can think of off the top of my head...

Doug

Do the hex on a mill

Just put a piece of HHS square rod in one of your tool holders and move it to sit on one of the flats of the hex on the end.
Then just G0 to that location for each part.

Doug
GENERALDISARRAY
VW_CHUCK (it says you live in PA, but there's a VW Chuck here in MN too, machinist/welder also)

Thanks for the responses.
It would be a few thousand pieces, each order.
We have a rotary axis for our mill, currently running beyond capacity already.

After tossing different ideas around in my head, I was thinking maybe I could use something similar to a 16C deep collet stop with the negative of the hex milled into it and indicate that to C0???
Kind of similar in idea, I think??

vw_chuck said:

Just put a piece of HHS square rod in one of your tool holders and move it to sit on one of the flats of the hex on the end.
Then just G0 to that location for each part.

Click to expand...

How does that work, with the previously machined hex out of sight, inside the spindle tube?

Regards,

Bill