Re: CNC Injection Mold Machining

I did some injection mod work when I was just out of high school.

The guys would hand mill the pockets and at that time we had a DRO as
the high tech stuff in the shop. (yeah, ancient history)

then the last few thousandths were taken out by hand. I still have
an assortment of different grade stones for taking out the milling
cutter marks, then takiing out the rough stone marks, then taking out
the streaks, then getting a prepolish on the part, and of course, the
final polish. wouldn't take more than a few days to make a mold, at
$100.00 an hour of course.

The next shop we did punches for the auto industry. there was rough
lathe work followed by a bunch of grinding machines after the stuff
was hardened.

that shop had one EDM, a plunge unit, I assume was before wire was
available. But I'm not sure of that history.

Now, one guy with an EDM can do one mold, both cavities, and to
higher tolerances that we could. of course, we did all measuring by
hand back then. Seems we might have had Bhrountasourous Burgers for
lunch !

Now, EDM is typical in a well stocked home shop and PC Magazine
offers a desk top laser for your office !

Dave




Dave



--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Randy Bachmann"
<r.bachmann@a...> wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Steve" <s.bromley@a...>
> wrote:
>
> > You sound like a cnc sales man talking to an engineer or ceo :)
>
> I have to laugh because I am neither a salesman or an engineer. I
> have a 2'x'4' laser in my garage shop and I am always looking for
> new production methods. I've contracted injection mold tooling
> though a local company and am trying to understand why the cost of
> tooling molds is so high. I don't think I am naive about the

process

> I know a lot goes into making molds and tool makers are skilled at
> what they do, hence they are probably paid well. I've seen laser
> cutters for mold making but they have their limitations.
>
> Randy
>
> There is
> > still the problem of ejector pins, water lines (that need to be
> run in ways
> > that aren't that simple) sprues, gate drops, hot tips, slides,
> gibs, locks,
> > lifters..... and dozens of other little parts. Lots of molds are
> as complex
> > as a car motor and have as many moving parts as well as as many
> parts that
> > need to be heated and cooled. There is also the thing, that you
> really want
> > to make some parts of the mold out of one kind of steel and other
> parts out
> > of other kinds of steel.
> >
> > It's more automated then it was when I started and I'm sure
> will get more
> > automated. I don't see the day that you will be able to just

throw

> two
> > blocks of steel into a machine and have it dump out finished
> molds. Not
> > production tools, maybe hand cast prototype stuff, that's
> basically there
> > now.