Mounting Power Chuck to Hardinge T42 Lathe?

I recently bought a couple Hardinge T42 lathes. I am trying to figure out the specs for what kind of power chuck fits them, and having some difficulty. They have A2-5 spindle noses and the 16C collets thread directly on to the drawbar. As far as I can tell, nearly all power chucks have a draw nut that the draw tube threads directly on to. The part where I am confused is that the draw tubes on these lathes are not long enough to extend out of the spindle nose and thread into a chuck.

I have found a video on the Hardinge youtube channel of them installing a Hardinge Sure-Grip power chuck on a lathe; the chuck has an adapter that joins the chuck to the draw tube. The adapter basically looks a shorter version of the draw tube itself. However, I cannot find any sign on the Hardinge site that they still sell these chucks, chuck adapter tubes, or anything of the like. And from shopping around other power chuck manufacturers, this does not look like standard practice for power chucks. It looks like all other machine types have a long enough drawbar that threads directly into the chuck draw nut.

Am I missing something or do Hardinge lathes (at least the T42s) actually require some sort of drawbar adapter for power chucks?

yes, you will need an adapter. Sort of an extension of the draw tube, as you describe. Many 6" power chucks will fit a A-2-5 spindle nose. For instance, my Haas SL10 has an A2-5 spindle nose. In my case, I had to have a A2-5 extension and adapter to fit 16C collets, so adapting the other way from your setup. You'll need to know the distance from the spindle face to the end of the draw tube in closed and open positions, and the thread. Hardinge tech support will likely be able to help. Good luck with your lathe!

Depending on the size of your draw-tube and the chuck you choose, you may be better off with that shorter draw-tube arrangement.
On my Mazak the factory draw-tube extends about 25mm beyond the spindle nose.
The through-hole in my 8" chuck is too small for the M55-2.0 threaded drawtube and I have to switch to a shorter draw-bar for the chuck.

Most of the time I run a Hardinge collet nose. That came with a 60mm thread-adapter for the larger series of lathes.
I have 55mm, so I grabbed a short piece of A2 and machined a new adapter.
Just like Eaglemike said, you need the distances from the nose, thread sizes, etc.

If you can't find the original stuff, it's pretty easy to come up with something that works properly:

It's actually quite simple, the chuck has a short draw tube arrangement, it is basically the non-business end of a 16C collet permanently mounted in the chuck. To mount the chuck, remove collet, place chuck in spindle and tighten as if it were a collet. When the back of the chuck is on the spindle face, place and tighten the 3 - 7/16"-14 SHCS thru the chuck. Adjust the chuck/draw tube combo to hit mid travel on your part.

The chuck should be available from Hardinge, but you could also roll your own based on the above description.


Steve