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Mike W
03-08-2004, 03:13 AM
I have a ram off of a log splitter. What could I use for a pump to make a hydraulic shop press. Feel free to be creative. I wouldn't use it that often so how slow the ram moved is not important.

Thrud
03-08-2004, 03:17 AM
Hydraulic hand pump or a powered pump would be fine.

Yankee1
03-08-2004, 03:25 AM
How about a powersteering pump off a vehicle. You will need an open center valve and a reservoir.You can either divert the
fluid with the valve or allow it to run through the open center back to the reservoir.Or you could use a bypass valve to build pressure in the system by preventing the fluid from going back into the reservoir, then the valve would not have to be open center. You will be using
whatever pressure the power steering pump
is set at. They are about 360 psi.
yankee1

Mike W
03-08-2004, 04:05 AM
What I know about hydraulics would fit in a thimble. How much pressure would I need to have available at the pump to end up with a decent press.

barts
03-08-2004, 04:29 AM
You can use a piece of 5/8" smooth rod running
inside 1/2" brass pipe w/ two o-rings on the
end and a couple of checkvalves & a tee.

Whatever you use, get all the air out - any
air left in the system makes it spongy and
much more likely to hurl things, which is
exactly what you don't want when the pressure
is on....

- Bart

Paul Gauthier
03-08-2004, 03:21 PM
How long is the cylinder??? Log splitter cylinders are usually about 24" that would not make a very good cylinder for a press, too long could be dangerous, and will nessecitate a very tall press. Actually now that I think about it, press hight would not be a problem with the right mounting technique.
About the pump, a two stage pumb driven by a 12 volt starter motor should work well. The valve you use should have a pressure relief valve.

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Paul G.

Mike W
03-08-2004, 03:55 PM
Keep the ideas coming. I thought about a hand pump but they are kind of pricey.

Evan
03-08-2004, 04:20 PM
Why not use a bottle jack?

John Stevenson
03-08-2004, 04:44 PM
Do the tail lift vehicles in the US have a self contained powerpack as ours do in the UK?
Ours are usually 24v off the vehicle batteries but the motor could be swapped over for a mains one.
In fact these power packs we use are also available in 240v single phase and 440v 3 phase for just this application.
I found a brand new power beam, ram, pump and valves in the scrap and bolted and welded a press up from this.
http://homepage.ntlworld.com/stevenson.engineers/lsteve/files/press1.jpg

The cylinder has a stroke of 16" and is 4" diameter. The pump can exert 5,000 psi max so the capacity is Pi x radius squared x 5,000 to give answer in pounds force and then divided by 2240 to give the same in tons.
So in my case this works out to 62,832 pounds or 28 tons max pressure.
The pump isn't visible in the picture but it sits along the rear of the beam and is powered by a 1hp 440 volt motor.

John S.

chkz
03-08-2004, 08:13 PM
why.....thats just a coffee table

Just kidding! Nice looking machine & nice pic!!

lynnl
03-08-2004, 08:57 PM
Hey John, that's a GREAT idea! ...painting tools bright colors so they can be easily found. I bet that saves a lot of time looking and digging around for them.
I'll have to remember that.

Looks good. ...like all your stuff.

docsteve66
03-08-2004, 10:40 PM
I just consulted Dodge factory manual on power steering pumps. At engine speed of 600-800 RPM the pump is considered failed unless it develops over 900 psi.

Figure a decent pump will give 1000 psi. If your Ram is 4", and if pi were 3 you would have 12,000 pounds force one way and less (subtract the rod area from the piston area) in the other direction.

No volume figures were listed, but they are pretty low for most uses (like log splitting) but should give an easily controlled ram for a press.

I think a ten/20 ton bottle jack would work better- a six ton (12,000) press may be light. I've done near chin ups on a 20 ton jack handle (so I was way over stressing the jack) and wished for more.

If you wish more volume and pressure go for a real hydraulic pump. I have had good luck with "prince" pumps and rams in the past (all the usual disclaimers) and they are on the low end of price range.

Be sure to have a relief valve (with adjustment easy to reach) in the line. Reason for having the valve available is that sometimes it nice to not have too much force applied or (more likely) you will "two block" the control to get the most pressure you can even at risk of pump damage. Having the adjustment available makes it more likely that you will restore to proper setting. a pressure gauge is a nice accessory too. Very calming to see the needle go into what ever you mark as the red line on the gauge just before the lines rupture. be sure to cover every thing so the high pressure oil does not hit you. It can cause loss of limbs or a slow painful death just from getting under the skin and into the meat. Think it all through and try to have a weak point some where so any failure will be safe.

I suggest you design and build the frame with provisions for easy modifications for either a ram or jack.

wierdscience
03-08-2004, 11:08 PM
Notice the mining helment in John's pic,it must really get deep in there http://bbs.homeshopmachinist.net//biggrin.gif

Power steering pump for rapid travel,needle valve and hand pump for delicate jobs,best of both worlds.

motorworks
03-08-2004, 11:23 PM
I built a 50t press about 6-7 years ago.Got most from Princess Auto.
Made my bed about 4' wide so I could get ATV axles in there to straightened.Also used a hand winch to rise and lower the bed.(Saves your back in a one man shop!)Go with an electric pump.Saves a great deal of time and effort.Put a box near by to hold all the jigs and plates you will make up.I found that large piston pins out of tractor engines come in handy.
Just be careful with it.It's the one thing in my shop that scares me!!
e

Mike W
03-09-2004, 12:14 AM
That is nice John. You guys have a lot of good advise. I appreciate it.

J Thornton
03-09-2004, 02:34 AM
If you go with the powered unit set up the controls so that you need to use both hands to operate it. Sure is nice to have all ten fingers. http://bbs.homeshopmachinist.net//biggrin.gif Might keep a friend from becoming a plaintiff.
Our rod straightener retracted the ram automatically
when we released the buttons. That might be handy too.

------------------
Jesse