On Fri, 1 Feb 2008 10:51:01 -0500, "Karl Townsend"
wrote:

I need to come up with a way to feed bar stock on my Hardinge CHNC. As I
don't have room for a real bar feeder, I'm looking for a way to feed short
bar stock, maybe 4' or 6'.

I seen this on eBay http://tinyurl.com/2sp8qz I'm sure it won't fit my
machine but it looks easy to build. Then I could just have a support tube
behind the spindle.

Anybody used one? Do they work well? I'm assuming you just use spring
tension/ deflection to hold and pull the bar stock as I see no air cylinder.
Correct?

Other good ideas to feed bar stock for an HSM type?

Karl


A simple bar puller may be made on the lathe.

Take a piece of bar stock at least .25 larger than the bar you are
trying to pull.

turn one one to fit your tool holder, typically 5/8"

Drill/bore the other end at least .010 smaller than the bar you want
to pull. Champher the end well.

Slit it all the way across with a hacksaw. Small stuff works ok with
a single slit, you may have to slit in a cross pattern for larger
stuff. If you are feeling yancy..consider heat treating it with a
torch if the puller material will heat treat to spring like
properties.

Bar is held in collet. Program slide move, so the new bar pullet
slides over the end of the bar. Friction grabs the bar.

Open collet closer. Retract bar to proper length, close collet, then
retract turret away from bar, bar slips out of puller, and index
turret to first work position. OR, use side of cutoff tool holder as
positioning device, open collet, move side of cutoff tool (or anything
you want to use for a stop), and push bar to proper length. Close
collet and make chips.

You can use pipe, conduit etc etc as a bar holder outside the machine.
All it needs to do is keep it centered and keep it from whipping.

Ive made literally hundreds of these bar pullers for clients

They work, are cheap and easy. You do need one for each different
diameter material you are working on, but simply write a program to
turn you out a couple dozen blanks, then as needed bore and slit.
If the bar puller wears, simply squeeze it down a smidge with a basic
regular old hose clamp.

These are also regularly used as a matter of course, in very small
stock diameters that preclude a pusher type bar feeder. Try using a
pneumatic bar feeder on a 1o' length of .020 wire G It bird cages in
the feeder tube. Like pushing string ...chuckle

Gunner