On 13 Jul 2003 21:31:17 -0400, (DoN. Nichols)
wrote:

In article ,
Gunner wrote:
On 13 Jul 2003 14:01:07 -0400, (DoN. Nichols)
wrote:


I've now finally gotten compressed air, so I may make up some
pistons for the pipes to use as stock feed devices, so I don't have to
stop the spindle to feed stock. Just add a foot switch -- and keep the
PVC leaky enough so it won't develop full pressure, perhaps with an
intentional leak at the end of stroke.

Enjoy,
DoN.

If you are running a turret, its very very easy to make a parts
Puller, rather than a pusher and you can simply make up a number of
pullers for various sized stock. The advantage of a puller over a
pnuematic or hydraulic pusher really comes into play with small
diameter stock.

I thought that the pullers were better in an ASM or perhaps a
CNC with turret -- with some way to activate them automatically. I
don't see a way of activating one on my turret. (And aside from that,
I'm already using all six stations on the turret, with the feed stop
running double duty as a center drill.)

1) Stop/center drill

2) Knurl OD

3) Box tool to reduce a portion of the OD

4) Geometric die head to thread un-knurled portion of the OD

5) Drill for tap

6) Tap

(then to the carriage for grooving at the base of the thread and
parting off while I break the edges with a file.) Next setup I'll be
using one of the multi-tool Aloris holders so I can do the parting of
the current one and the grooving of the next in a single pass.

Enjoy,
DoN.

In lue of the parts stop, make a puller. Simply bore a chunk of Crs or
other common metal to .005 smaller than your work, and turn the other
end to fit your turret. Then slit the bored end lengthwise.

Extend your work, close the collet. Extend the puller and it will slip
over the end of your work piece. Release the collet, and retract the
puller to the proper distance. Close the collet, retract the puller a
smidge more, pulling it off the workpiece. The first pull is marked or
set as your dead stop. Proceed with the rest of your operations. The
stub should be long enough now to slide the puller over it, retract,
and proceed. The puller is only a friction fit over the end of your
bar.

Countless machine shops use a puller every day, even on CNC,
particularly for short bars.

The second type of "bar feeder" is one that is gravity fed, and is
very easy to make in a home shop. Simply slot a piece of galvanized
pipe lengthwise, and make up a slider that fits inside, with a stub
protruding through through the slot. Attach a cord to the stub, and at
the end closest to the lathe, on the front support, attach a rotating
drum, and wrap the cord around the drum, and hang a weight from it.
As you slide in the bar, it winds up the weight. Gravity wants to pull
the weight down, putting feed pressure on the bar stock. Virtually all
of the Traub, Tornos, etc etc Swiss style screw machines use this
simple and effecient type of bar feeder.

And its a snap to make any length you have room for.

Gunner

"What do you call someone in possesion of all the facts? Paranoid.-William Burroughs