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Default DIY hydraulic presses, with electric pumps

Awl --

In particular, how does one size the motor/pump for a given tonnage? Say,
10 tons. Is tonnage the only issue? See below.

My buddy needs one made, is getting a price, but it seems like the price
keeps climbing, and they are claiming he needs 7.5 hp for 10 tons.

We had a Daco 55 ton press, and I'd swear that press had only mebbe a 1-2 hp
motor.

BUT, it operated very slowly.

I would imagine for a *faster* stroke at a given tonnage, hp increases, as
the hydraulic "mechanical advantage" is probably decreasing with increased
speed, so a bigger motor is req'd.

How to calc??

Iny links to DIY sites around?

Thanks,
--

Mr. PV'd

Mae West (yer fav Congressman) to the Gangster (yer fav Lobbyist):
Hey, Big Boy, is that a wad (of cash) in yer pocket, or are you just
glad to see me??




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Default DIY hydraulic presses, with electric pumps

"Proctologically Violated©®" wrote in message
...
Awl --

In particular, how does one size the motor/pump for a given tonnage? Say,
10 tons. Is tonnage the only issue? See below.

My buddy needs one made, is getting a price, but it seems like the price
keeps climbing, and they are claiming he needs 7.5 hp for 10 tons.

We had a Daco 55 ton press, and I'd swear that press had only mebbe a 1-2
hp motor.

BUT, it operated very slowly.

I would imagine for a *faster* stroke at a given tonnage, hp increases, as
the hydraulic "mechanical advantage" is probably decreasing with increased
speed, so a bigger motor is req'd.

How to calc??

Iny links to DIY sites around?


Oh, it just dawned on me:

I in fact have an 80 ton bottle jack (manual), AND two hydraulic
pumps/resevoirs from an old car lift.

Is it straightforward to attach a hydraulic pump to a hand bottle jack?
If so, what types of parts/valves/etc are req'd? DIY site?

--

Mr. PV'd

Mae West (yer fav Congressman) to the Gangster (yer fav Lobbyist):
Hey, Big Boy, is that a wad (of cash) in yer pocket, or are you just
glad to see me??








Thanks,
--

Mr. PV'd

Mae West (yer fav Congressman) to the Gangster (yer fav Lobbyist):
Hey, Big Boy, is that a wad (of cash) in yer pocket, or are you just
glad to see me??






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Default DIY hydraulic presses, with electric pumps

On 2009-02-21, Jim Wilkins wrote:
On Feb 21, 11:58*am, "Proctologically Violated©®"
wrote:
Awl --

In particular, how does one size the motor/pump for a given tonnage? *Say,
10 tons. *Is tonnage the only issue? *See below.


You can achieve almost any tonnage with any pump given a big
enough slave cylinder and enough time. Work from the diameter of the
slave cylinder and the required force to calculate how much hydraulic
pressure is needed -- and then go from that to find out how fast a pump
you need.

I've got three ways to power the crimping heads by AMP for wire
sizes from 1/0 through 4/0.

1) An EnerPac hand pump

2) A foot pump sold by Amp for the purpose.

3) An electrical pump (once) sold by AMP for the purpose.

Of the three, the second one gives the best feel of what is
happening. With nothing in the dies and the dies open, about two strokes
is more than enough to close the dies and hit the pressure release (set
to about 8500 PSI). The switchover from high volume to high pressure is
close to instant.

With a 4/0 terminal in the dies, and 4/0 wire in the terminal, I
feel a little back pressure on the pedal as the terminal starts to
deform, and up to nearly fully crimped. (This takes several strokes).
Then the force required decreases noticeably as the high pressure slow
pumping mode switches on, and the crimp is completed in this mode.

The electrical pump doesn't even seem to change sound as it goes
through these stages up to the 8500 PSI release point.

The EnerPac hand pump takes more effort (of course it doesn't
have as long a lever, and it doesn't have my weight behind it.

The total stroke for this task is only about 1/2 to 3/4", so
slow pumping is not a real problem.

My log splitter uses a 5.5 HP gas engine to run an 11 CFM Barnes two-
stage pump, driving a 3.5" cylinder at up to 2500 PSI. This works out
to 12 tons. The parts all came from Northern Hydraulics long before I
bought the thing. When the pump shifts to low range the piston speed
is a little more than I'd want for a press unless it was doing a
predictable production job. Otherwise log splitter hydraulic hardware
seems reasonable. Anyone else try this?


I've not tried it, since I have had the electrical AMP pump for
a couple of decades before I finally got the crimp heads and dies to go
with it. (One of those things in a government surplus auction which I
had not even noticed until it was time to pack the stuff into the car.
:-)

The engine will drive the pump to 2500 PSI at about 3000 RPM, a sweet
spot for low vibration. It stalls if I set it much lower so I don't
know how well it would work if you direct-coupled the pump to a 1725
RPM motor. Not all low-cost hydraulic pumps have bearings suitable for
a pulley's side load.


Unless your hydraulic press is designed to accept the 8500 PSI
range, I would suggest avoiding the crimper pumps (foot or electrical),
as it could be easy to over-pressure it and break something.

If you're interested in one of the foot pups at what I consider
an excessive price, take a look at eBay auction #330055769330. They've
got a $950.00 buy-it-now and have had it for a couple of months at
least. I got mine during the lifetime of this "auction", from eBay, for
a bit under $300.00, which I considered a reasonable price. The only
other differences between them was that the one I got was yellow (as was
the one I used back around 1964 or so), and this is blue, and the one i
got had a link to where you could download the PDF for the manual, and
this one they appear to have downloaded and printed the manual for you. :-)

Here's a somewhat larger (3HP) electric pump to 10,000 PSI on
eBay -- if you are interested in shoveling out some money. :-)

# 140079292295

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
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Default DIY hydraulic presses, with electric pumps


"Proctologically Violated©®" wrote in message
...
"Proctologically Violated©®" wrote in message
...
Awl --

In particular, how does one size the motor/pump for a given tonnage?
Say, 10 tons. Is tonnage the only issue? See below.

My buddy needs one made, is getting a price, but it seems like the price
keeps climbing, and they are claiming he needs 7.5 hp for 10 tons.

We had a Daco 55 ton press, and I'd swear that press had only mebbe a 1-2
hp motor.

BUT, it operated very slowly.

I would imagine for a *faster* stroke at a given tonnage, hp increases,
as the hydraulic "mechanical advantage" is probably decreasing with
increased speed, so a bigger motor is req'd.

How to calc??

Iny links to DIY sites around?


Oh, it just dawned on me:

I in fact have an 80 ton bottle jack (manual), AND two hydraulic
pumps/resevoirs from an old car lift.

Is it straightforward to attach a hydraulic pump to a hand bottle jack?
If so, what types of parts/valves/etc are req'd? DIY site?

--

Mr. PV'd


At work we have a press that uses an air cylinder to pump a hand type pump.
It might be easier to use an air cylinder to pump the bottle jack.
Otherwise you have to try to find a way of getting the fluid in to the high
pressure side of the bottle jack. I'm wondering if you could remove the
bottle jacks pump piston, make a duplicate and drill a hole through it for
hydraulic fluid, that might work.

RogerN


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Default DIY hydraulic presses, with electric pumps

Proctologically Violated©® wrote:
Awl --

In particular, how does one size the motor/pump for a given tonnage? Say,
10 tons. Is tonnage the only issue? See below.

My buddy needs one made, is getting a price, but it seems like the price
keeps climbing, and they are claiming he needs 7.5 hp for 10 tons.

We had a Daco 55 ton press, and I'd swear that press had only mebbe a 1-2 hp
motor.

BUT, it operated very slowly.

I would imagine for a *faster* stroke at a given tonnage, hp increases, as
the hydraulic "mechanical advantage" is probably decreasing with increased
speed, so a bigger motor is req'd.

How to calc??


Power = Force x Velocity (there may be a constant involved if you use
imperial units). I figure that using a 7.5 hp motor and a 10 ton load,
you get about 2 inches per second at 100% efficiency. But I doubt you'll
get more than half that in reality.

And you probably don't need maximum force and maximum velocity at the
same time. So you can get better performance using a two-stage pump
which can supply a high flow rate at a low pressure or a low flow rate
at a high pressure and switch automatically between the two.

It's worth noting that an electrically powered press is a lot more
dangerous than a hand powered press. If you're using a hand powered
press and you get your hand trapped in it, you stop pumping because it
hurts. A motor won't do that.

Best wishes,

Chris



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Default DIY hydraulic presses, with electric pumps


"Proctologically Violated©®" wrote in message
...



"Jim Wilkins" wrote in message
...
On Feb 21, 11:58 am, "Proctologically Violated©®"
wrote:
Awl --

In particular, how does one size the motor/pump for a given tonnage? Say,
10 tons. Is tonnage the only issue? See below.


My log splitter uses a 5.5 HP gas engine to run an 11 CFM Barnes two-
stage pump, driving a 3.5" cylinder at up to 2500 PSI. This works out
to 12 tons. The parts all came from Northern Hydraulics long before I
bought the thing. When the pump shifts to low range the piston speed
is a little more than I'd want for a press unless it was doing a
predictable production job. Otherwise log splitter hydraulic hardware
seems reasonable. Anyone else try this?

The engine will drive the pump to 2500 PSI at about 3000 RPM, a sweet
spot for low vibration. It stalls if I set it much lower so I don't
know how well it would work if you direct-coupled the pump to a 1725
RPM motor. Not all low-cost hydraulic pumps have bearings suitable for
a pulley's side load.

======================================

I may have stumbled on an even easier solution:
http://www.mytoolstore.com/astro/asthyd01.html

shows a 12 ton air-operated bottle jack. I would assume the travel is
orders of magnitude faster than manually pumping the jack.

$150 gets a 20 ton.

All's I gotta do is build something of a frame for it, and it should be
good.

At $76 for the whole unit, I don't think I could get a lovejoy coupling
for a hydraulic motor/pump.


You could get a press from harbor freight for about $120.00 and put the jack
on it you pointed out.

http://www.harborfreight.com/cpi/cta...temnumber=1667

Or you could get a bigger press for the 20 ton jack from them also at
$239.00.

http://www.harborfreight.com/cpi/cta...emnumber=32879

Richard W.


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Default DIY hydraulic presses, with electric pumps

On Sun, 22 Feb 2009 22:53:57 +0000, Christopher Tidy
wrote:

Proctologically Violated©® wrote:
Awl --

In particular, how does one size the motor/pump for a given tonnage? Say,
10 tons. Is tonnage the only issue? See below.

My buddy needs one made, is getting a price, but it seems like the price
keeps climbing, and they are claiming he needs 7.5 hp for 10 tons.

We had a Daco 55 ton press, and I'd swear that press had only mebbe a 1-2 hp
motor.

BUT, it operated very slowly.

I would imagine for a *faster* stroke at a given tonnage, hp increases, as
the hydraulic "mechanical advantage" is probably decreasing with increased
speed, so a bigger motor is req'd.

How to calc??


Power = Force x Velocity (there may be a constant involved if you use
imperial units). I figure that using a 7.5 hp motor and a 10 ton load,
you get about 2 inches per second at 100% efficiency. But I doubt you'll
get more than half that in reality.

And you probably don't need maximum force and maximum velocity at the
same time. So you can get better performance using a two-stage pump
which can supply a high flow rate at a low pressure or a low flow rate
at a high pressure and switch automatically between the two.

It's worth noting that an electrically powered press is a lot more
dangerous than a hand powered press. If you're using a hand powered
press and you get your hand trapped in it, you stop pumping because it
hurts. A motor won't do that.

Best wishes,

Chris




Use air over oil, and a small pump to move to the top of the part.

I just completed a 700 ton and a 200 ton ,closed loop, air over oil .

Used a plc and hmi for programming both ramp and target pressure.

Dave B
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Default DIY hydraulic presses, with electric pumps

On Feb 22, 6:05*pm, Dave B wrote:

Use air over oil, and a small pump to move to the top of the part.


That can be dangerous: compressed air stores significant
energy, it can shatter an item in the press and send pieces
flying. With oil only, an item in the press shatters and the
oil pressure immediately drops, before projectiles form...

My preference is for a two-stage pump, either hand or
power, so the piston moves to take up slack at the fast speed,
then falls back to the slow speed when the pressure rises.
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Default DIY hydraulic presses, with electric pumps

On Mon, 23 Feb 2009 11:49:43 -0800 (PST), whit3rd
wrote:

On Feb 22, 6:05*pm, Dave B wrote:

Use air over oil, and a small pump to move to the top of the part.


That can be dangerous: compressed air stores significant
energy, it can shatter an item in the press and send pieces
flying. With oil only, an item in the press shatters and the
oil pressure immediately drops, before projectiles form...

My preference is for a two-stage pump, either hand or
power, so the piston moves to take up slack at the fast speed,
then falls back to the slow speed when the pressure rises.



It is not if you use a correct intensifier.

http://www.airhydraulics.com/Hydraul...aulicPress.htm


It's done everyday.
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Default DIY hydraulic presses, with electric pumps

On Mon, 23 Feb 2009 11:49:43 -0800 (PST), whit3rd
wrote:

On Feb 22, 6:05*pm, Dave B wrote:

Use air over oil, and a small pump to move to the top of the part.


That can be dangerous: compressed air stores significant
energy, it can shatter an item in the press and send pieces
flying. With oil only, an item in the press shatters and the
oil pressure immediately drops, before projectiles form...

My preference is for a two-stage pump, either hand or
power, so the piston moves to take up slack at the fast speed,
then falls back to the slow speed when the pressure rises.




Here are some of the presses I have done (last year)

Air over oil,air intensifier and closed loop servo valve

http://s32.photobucket.com/albums/d1...nt=200ton3.jpg

http://s32.photobucket.com/albums/d1...nt=200ton2.jpg

http://s32.photobucket.com/albums/d1...ress_Retro.jpg

Dave B


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Default DIY hydraulic presses, with electric pumps


"Dave B" wrote in message
...
On Mon, 23 Feb 2009 11:49:43 -0800 (PST), whit3rd
wrote:

On Feb 22, 6:05 pm, Dave B wrote:

Use air over oil, and a small pump to move to the top of the part.


That can be dangerous: compressed air stores significant
energy, it can shatter an item in the press and send pieces
flying. With oil only, an item in the press shatters and the
oil pressure immediately drops, before projectiles form...

My preference is for a two-stage pump, either hand or
power, so the piston moves to take up slack at the fast speed,
then falls back to the slow speed when the pressure rises.




Here are some of the presses I have done (last year)

Air over oil,air intensifier and closed loop servo valve

http://s32.photobucket.com/albums/d1...nt=200ton3.jpg

http://s32.photobucket.com/albums/d1...nt=200ton2.jpg

http://s32.photobucket.com/albums/d1...ress_Retro.jpg

Dave B


Very nice. But that makes a two or three stage pump look very simple.


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Default DIY hydraulic presses, with electric pumps

On Mon, 23 Feb 2009 22:04:22 -0600, "Elliot G"
wrote:


"Dave B" wrote in message
.. .
On Mon, 23 Feb 2009 11:49:43 -0800 (PST), whit3rd
wrote:

On Feb 22, 6:05 pm, Dave B wrote:

Use air over oil, and a small pump to move to the top of the part.

That can be dangerous: compressed air stores significant
energy, it can shatter an item in the press and send pieces
flying. With oil only, an item in the press shatters and the
oil pressure immediately drops, before projectiles form...

My preference is for a two-stage pump, either hand or
power, so the piston moves to take up slack at the fast speed,
then falls back to the slow speed when the pressure rises.




Here are some of the presses I have done (last year)

Air over oil,air intensifier and closed loop servo valve

http://s32.photobucket.com/albums/d1...nt=200ton3.jpg

http://s32.photobucket.com/albums/d1...nt=200ton2.jpg

http://s32.photobucket.com/albums/d1...ress_Retro.jpg

Dave B


Very nice. But that makes a two or three stage pump look very simple.

Wasn't meant to be simple.

I just stated for the op to use air over oil............very simple

Dave B
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Default DIY hydraulic presses, with electric pumps

On Saturday, February 21, 2009 at 10:58:33 AM UTC-6, Proctologically Violated©® wrote:
Awl --

In particular, how does one size the motor/pump for a given tonnage? Say,
10 tons. Is tonnage the only issue? See below.

My buddy needs one made, is getting a price, but it seems like the price
keeps climbing, and they are claiming he needs 7.5 hp for 10 tons.

We had a Daco 55 ton press, and I'd swear that press had only mebbe a 1-2 hp
motor.

BUT, it operated very slowly.

I would imagine for a *faster* stroke at a given tonnage, hp increases, as
the hydraulic "mechanical advantage" is probably decreasing with increased
speed, so a bigger motor is req'd.

How to calc??

Iny links to DIY sites around?

Thanks,
--

Mr. PV'd

Mae West (yer fav Congressman) to the Gangster (yer fav Lobbyist):
Hey, Big Boy, is that a wad (of cash) in yer pocket, or are you just
glad to see me??


http://www.surpluscenter.com/Tech-He...sp-HP-GPM-RPM/

http://www.surpluscenter.com/Tech-He...eed-Torque-HP/
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