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How deep do hydraulic presses press


#1

Hi Everyone,

How deep do hydraulic presses press? I want to make some boxes.
Also, are the pressed results always super curved? I don’t need an
exact straight wall but I would like it to not be too bowled.

Thanks,
Isabel


#2

You can get tooling to make 90degree bends with the press but a
break is what most bending is done on in the sheet metal trades.

Sam Patania


#3

Boxes, of whatever shape, in precious metal are invariably made from
sheet, that has the corner cut outs done with a shear.

then all the box inside bend lines are scored with a 90 Deg graver
half way through the sheet.

then these score lines become the fold points.

The seams are trued up to a close contact and soldered.

If you want to press out a box shape, ie whats called deep drawing
you would need a whole lot of press tools in steel with a deep
drawing fly press to suit to get any worthwhile use of your time. its
not the tonnage you need, its the stroke.

Look around at boxes in steel, ie like old tobacco tins etc.

they all have rounded corners. If rounded corners are your design,
then it can be done as outlined above.

You wont be able to press corners into a sharp angle.


#4

Isabel,

Most jewelry studio presses can deep-draw metal with straight sided
walls to about 5" to 6" in depth. I’m guessing from your stated
observation, “always super curved”, that you are referring to
silhouette dies. Though it is possible to use a silhouette die to
make boxes you will find it very difficult to get straight sided
walls.

Deep-drawing is a process which creates straight-walled vessels from
sheets of metal. The Bonny Doon Volume and Form press can deep-draw
16" or 18" in depth with 18" diameter discs, and the BD Tubing press
is designed to make 12"-13" lengths of ring-sized tubing using 6"
discs of metal. The Classic and MKIII BD presses are capable of
deep-drawing 3" and 6" discs respectively.

I hope this helps,
Sincerely,
Phil


#5

Hi Ted,

There is a deep draw setup for the Mk II and Mk III Bonny Doon 20
Ton hydraulic presses. They do have enough stroke to do deep drawing
with up to 6" blanks. There’s a 12" blank deep draw rig for the 50
ton BD presses, but those are not precisely common beasts. (I think
there was at least one 18" deep draw rig as well, but I could be
wrong.)

There were a couple of experimental square deep draw sets for them
as well. Radius’ed corners, but still square, more-or-less. Never
released to commercial sale, but they did/do exist, and run on basic
hydraulic presses.

Neither system required a massive amount of tooling. One master die,
and then steppers down from there, along with punches, strippers and
alignment collars. Which sounds like a lot, but isn’t as horrible as
it sounds. Heavy, and slick as the devil, what with all the lard,
but not insupportable.

FYI,
Brian

PS–> To the OP: Ted’s right about the practicalities of making
boxes though. The smallest of the deep draw kits I’m talking about
sells for about $2K US, and the 6" is $4230. The larger ones are
somewhat more expensive. The square ones would be more, much more.

So unless you’re planning on making a production line of these
things, fabricate them.


#6

Oh OK, thank you for the differences, that helps. I’m looking to
make shallow boxes, no deeper than an inch, and would be OK with some
curvature on the bottom. I would like to be able to press a pattern
in the top of it as well. Could I press the box and then have a
shallow sillouette die and repress and get the pattern in?

Thanks,
Isabel


#7

oh wait a minute, just saw the pricing on those deep draw tools.
Time to reconsider…


#8

Never seen the Bonny Doon range here in the UK.

My hyd press is for coining. up to 250 tons.

A real die breaker.

And yes, tooling isnt cheap. my minting dies run to hundreds of $.

Tho Ill gt 20,000 impressions from them before they get tired.

The other way I deliver energy is with drop hammers. the most used
is 275lbs dropping 36ins.

This enables me to hot work metal, also its quick. 300 an hr cold
striking when everything goes right.


#9
Oh OK, thank you for the differences, that helps. I'm looking to
make shallow boxes, no deeper than an inch, and would be OK with
some curvature on the bottom. I would like to be able to press a
pattern in the top of it as well. Could I press the box and then
have a shallow sillouette die and repress and get the pattern in? 

Boxes can have tops but there usually called lids.

Can be just an interference fit over an internal strip or flange or
hinged with or without a catch or lock.

it all depends on what you are making the box for, from what metal
and what price you think you can get for it…

As for pressing a design into the top or lid!! yes that can be done
with a 2 part hardened tool steel die one a positive, usually set up
in the uppermost part of your tool set and the negative replica of
the positive in the bottom.

you register the sheet accurately!! in between the 2 dies and apply
the load.

Thats effctively doing repusse all in one go.

Taking this technique as far as you can go is coining to proof
quality.

For that you need hundreds of tons of load.

Really big kit to do this type of work, with a factory to put it in,
but great to use.

This is in the realms of a fully industrialised setup.

Research the history of the US Co. the Metal Box Co.


#10

Hi Ted,

There are a bunch of them in the basement at Birmingham, (School of
Jewellery), and I think the Cass has a few in London as well, if you
get out that way.

Not precisely common over there, but they do turn up.

Regards,
Brian