[TheForge] 15Ton Press

[Ralph Sproul]

        Ed, the term compensated indicates the pressure is varied.  The main
purpose of these pumps is to have an "idle" so the oil doesn't heat up when
left running all day, and then kick in when needed to do the work.
        I'd stick with the two stage pump you mention - it will give you
fast there, and slow to work under the heavier pressure.  The pressure
relief valve in your valve body determines the break out pressure of the
system.
        It's not so much the pressure that determines the rolls being
driven, it's the size of the vanes in the rotor of the motor.  You buy a
motor with higher torque ratings, not one that works with higher pressures.
        I also had a pilot pressure cylinder off a crane outrigger that I
used for my ram.  I bored the pilot system out, and welded in a new port
fitting to over ride that system and make it a regular system.  If the pilot
pressure is too high, your pump will always be on high pressure even to move
the cylinder, which will defeat the entire purpose of having a two stage
pump, and then the press will be to slow to do anything.
        Welcome to the wonderful world of scrounging hydraulic parts and
finding it often is better to just buy what you need, as compared to the
hours of work it takes to make what you found work.  :-)
        I made a set of cut offs for choping off 2 1/2" stock hot.  Works
but rather rough,  I saw the parts - then press them hot.

Ralph Sproul - Bear Hill Blacksmith
Webster, NH


----- Original Message -----
From: "Ed Fasula" <edfasula@yahoo.com>
To: "TheForge" <theforge@mailman.qth.net>
Sent: Thursday, January 03, 2002 10:29 PM
Subject: Re: [TheForge] 15Ton Press


> Hi Chuck & Ralph,
>
> I'm really interested in your ideas about using rollers.  I'm designing my
> press and I'd like to keep this future design in mind.  I haven't bought a
> pump yet - the compensated piston pump sounds interesting - do you
> basically set it at a given pressure?  Is it just one speed then?  I was
> planning on a Northern Hydraulics 2 speed gear pump, which wouldn't stop
at
> a pressure but my piston has a valve to lock it until forced to move -
it's
> off a construction fork lift.  So I could set it to a stock thickness.
Any
> idea on the power required to drive the roller?
>
> Chuck, I'm really interested in seeing the structure for a 70 ton
> press!  How wide is your span?  The book has a 10" opening.  I'd like to
go
> at least 12".  Have you ever wished to have it wider?  What is your die
> setup that you can change in 15 seconds?  I was thinking of using 3x3
> vertical bar and then plasma cutting blanks that I'd press around the 3x3
> bar (into a female die), that would form a box with one open end, then
have
> a hitch pin with a ball retainer to run horizontally through the 3x3 bar.
>
> Have you guys ever thought about making a hot shear with the press?
>
> Can you pass along some pictures?  Please use edf@hutchtel.net
>
> Ed
>
>
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