On Sat, 12 May 2012 20:06:28 -0700, Gunner Asch
wrote:

On Fri, 11 May 2012 09:40:52 -0400, Tom Gardner mars@tacks wrote:

On 5/11/2012 5:36 AM, Wild_Bill wrote:
snip
Halve it your way.


Good one!

1/2 of 1% gets cut in house, it's just a PITA. I've see the operation at
the the commercial cutter, they do it with a parting tool on a machine
that supports the tube from the inside and the outside, it's like a big
lathe with all automatic operations. The ID is chamfered with a reamer
type tool and the OD is chamfered with a grinding operation on another
machine. They WILL do the shorter lengths but with a 8-10 week lead
time. We also use miles of thicker tube, .062" wall that is no problem
with custom lengths cut in house but the .049" wall is delicate by
comparison and any imperfection will cause it to accordion or not swage
properly. When that happens it almost no worth recovering the parts.

I thought it was an interesting challenge and that maybe someone had
magic. I had no idea what it would turn into. I guess that RCM is
tuned to other things, too bad. But, most people DID offer good ideas
in the spirit of the old, old RCM.

So, my conclusion is to bite the bullet with the lead time from the
commercial cutter and keep shorter pieces on the shelf.

Tom..what you need to do is find an old Hardinge DV-59

Cross slide and turret.

Set up a cut off tool in the cross slide, and a mandrel in the
turret....or several mandrels in the turret
Bar feed in your stock. Put the mandrel at the correct length (distance
from the cutter. Infeed a length of tubing. Pull the turret forward
until the mandrel goes in the pipe, close the collet, hit the spindle
(and it really doesnt need to be shut off for any operation), lever in
the cut off slide, retract, retract the turret, pull off the cut piece,
slide it forwards again, open collet, infeed tube over mandrel, close
collet, cut off, repeat.

Dead simple and one can do a cut in about 2 seconds.

Run all the pieces you need. Then turn turret to handy hand made V
deburring tool in an offset on the turret, infeed, deburr..retract
turret, open collet and pull out work, reverse ends, close collet, hit
with deburring tool in turret, repeat as necessary.

Very much a no brainer and very very fast

One could even do this with a pneumatic bar feeder for extra speed and
minimal operator handling

Gunner


Gunner
This was pretty much the operation when I operated a manual cut off
lathe in a welded steel tube plant in 1971. IIRC the cut off tool was
mounted inverted to cut when the cross feed lever was pulled toward
the operator. Push the lever to open the collet and feed material to
the stop. The cut off tool was ground at a slight angle in order that
the partedoff piece had negligible burr, the burr being left on the
tube still held in the collet. This burr was manually removed with a
quick flick of a tool fashioned from a half round file. I don't recall
the production rate but I do recall that the feed rack was replenished
at least twice per shift by the overhead crane.