Thanks for the extensive explanation, James.
Always nice to learn something, especially when it's fringe-related to
one's interests.

I saw a couple of NG series on telly about "how things are made", and
I was mighty impressed with all these heavy machinery punchers and
presses and plasma cutters... quite fascinating. Sometimes scary too,
a bit.

Also a stunner to watch (on Apple's website): how a solid block of
aluminum is machined into something as refined as the latest MacBooks.

-g

On 22 Oct 2008, at 23:02, James Husted wrote:

> In most sheet metal work, the holes are not drilled and the metal is
> not sawed. The holes are typically punched out of the sheet metal
> (usually a 4 foot x 8 foot sheet) by a large multi-headed numerically
> controlled punching machine. The operator programs in all the hole
> locations and the type of tool used (round, square, oblong, hex, or
> special like a RS-232 connector) and its orientation if needed. The
> sheets are programmed to be punched with the highest yield of parts
> possible. That is why custom parts are expensive. You have to have a
> large part count to make it worth punching. Typically the metal shop
> will try to mix jobs from different clients using the same gauge
> metal to lower cost otherwise extra metal left over is recycled at a
> loss. The edges are punched with a series of long slot punches. You
> can see marks along the edge of a panel where the punches overlap
> unless a post-process sanding cleanup is done. Also typically the
> front face is called out and the job is specified weather the holes
> are to be punched from the front or rear surface. If you look closely
> at the edges of the holes you can see this as a very sharp edge on
> the exiting side and a small rounded edge on the side where the punch
> hits the metal. This get more obvious as the punch wears out and
> doesn't punch as cleanly.
> The type of holes that one can have punched are totally limited by
> the sheet metal house. It is limited by what punches they have in
> stock. Most houses will have a huge variety of round and square hole
> sizes and allot of the common slot sizes (used by rack ear holes for
> instance) along with commonly used custom holes like for IEC power
> connectors and computer serial connectors. Most odd shapes can be
> made by punching combinations of smaller holes too. If a client needs
> an odd shape hole that will be used a lot in a job, a custom punch
> will often be made to add to the sheet metal house's library.
> Doepfer's metal shop may not have the small slot punches mentioned
> and they may want way too much to make a custom punch.
>
> I hope that helps. I can tell you from experience that seeing a large
> sheet metal machine pound out a piece is very impressive. Here is a
> link to a site that shows the whole process: <http://www.industrial-
> computer-source.com/white_paper_sheet_metal.html>
>
> James
>
> On Oct 22, 2008, at 12:04 PM, Guy Drieghe D. wrote:
>
> >
> > James,
> >
> > Can you please enlighten the non-metal workers (and non-native
> English
> > speaking) amongst us as to what exactly "hole punch" and "slot
> punch"
> > thingies are
> >
> > tia !
> >
> > - Guy
> >
> >
> > On 22 Oct 2008, at 20:41, James Husted wrote:
> >
> >> Dieter-
> >> And thanks for making them! I know they are probably not a hugely
> >> selling product either. I have already hacked my AS stuff (and
> >> reducing it's resale prices accordingly). Unfortunately for me at
> the
> >> time I would not be willing to let go of 3-hp of panel space (one
> in
> >> each side of a bank of AS). Things are different now. As a old
> metal
> >> work guy I really see changing the hole punch currently used by
> >> everyone to a slot punch instead as a much better solution (Cwejman
> >> seems to be the only one doing this). That way any module can be
> used
> >> in any system. Changing punches should cost nothing more than a
> >> programming fee for older modules already in production and nothing
> >> for newer modules.
> >>
> >> -James
> >>
> >> On Oct 22, 2008, at 11:06 AM, yahoo@... wrote:
> >>
> >>>> The only other concern is the 1/2 a hp hole spacing difference
> from
> >>>> Doepfer and AS modules. Expect a gap or break out the drill
> press!
> >>>>
> >>>> -James
> >>>
> >>> As mentioned several times we have 1.5 HP blind panels available
> to
> >>> avoid
> >>> these gaps !
> >>>
> >>> Best wishes
> >>> Dieter Doepfer
> >
> >
> > [Non-text portions of this message have been removed]
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
>
>



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