"Tim Wescott" wrote in message
...
Ed Huntress wrote:
"Tim Wescott" wrote in message
...
If I wanted to buy a bunch of 4.5" long shafts, 3/16 or 1/4 inch
diameter, mill finish, with one end turned down to 4mm with a 1mm flat
(to make a "D" 4mm diameter and 3mm from flat to round), about 5mm or so
long, with the shoulder profile being quite unimportant.

Prototype runs of 10 or so, production orders of one or two hundred.

My understanding is that this is a job for an NC lathe, and that most if
not all of them would have an attachment for milling the flat, so the
operation would be feed, turn down, cut the flat, cut off, repeat.

What I'm not so sure of is where to find someone interested in those
sorts of volumes, and if I can get this below the $13 that the one
online machine shop I tried wants. I'm also not sure of where I can
compromise on specs to get the price down (the "D" probably has to be
+0 - 0.005", the shaft can probably vary +/- 0.005", since it'll be
running in plastic bearings).

Any guidance appreciated.

Do you know Dave Corgill? ("Why") I'd give him a call. He runs old
Brownies that might, or might not, have the capacity to handle those
shafts. The flats are something he'd probably do on his mill.

We did lots of simple jobs like that in an old manual-machine shop I
worked in, and they were mostly done in two setups. One setup with a CNC
mill/lathe may not be the most economical way to do it.

Dave's phone is 214-741-9062. He rarely answers; leave a message. His
wife passed away a few weeks ago, and I don't know if he's in gear yet or
not. But he's your man for shafts with second operations.

--
Ed Huntress
I guess it depends on how fast you can pump them through the machine vs.
how much time it takes to do the second operation on a second machine.

Well, I used to sell and market one of the better multifunction machines
(Wasino), and my opinion is that your job is unlikely to exploit any
advantage from a lathe/mill.


I could see this going pretty fast on a manual machine -- in fact I may
end up doing some of the work on a CAC* machining center. But I don't
really have a good enough mill to do this reasonably fast, and my lathe is
barely up to it.

You just need someone with better machines. I'd still call Dave. He could
give you some further thoughts, having done that kind of thing for a living
for around 40 years.

--
Ed Huntress