Shop Press Jack Location

Susan_in_SF

Susan_in_SF

Wood and Metal Goddess
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Jul 18, 2017
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Hi guys,
Although I have no space, I feel I need a shop press. I noticed there are 2 different shop press designs. One where the jack is under the top beam, and one where it's above. Does the jack location make any difference with the press' performance? I am attaching a couple of pics below.

Thanks,
Susan
s-l300 (1).jpg002-au-20411_1.jpg

002-au-20411_1.jpg
 
When I get around to building one it will be the jack above design. Think you could build a better guide system for the ram to be sure your pressing straight.

Greg
 
Hi Susan,
the pump (hydraulic jack) will be the deciding factor in the performance of the 2 different presses.
if one pump is good to 12 tons and the other is good for 20 tons, the 20 ton unit will be a heavier duty press.
most home type presses have some operational slop in their design, the industrial types are more precise in construction.
it is possible to take an inexpensive press and reinforce or modify the press for less clearance between moving parts.
most notably, the second press shown has a moving beam that the pump is attached to.
the clearance between the beam and the column sometimes can be excessive and cause the beam to distort under heavy use.
a common cure is to line the beam ends with delrin or bronze to keep the clearance tight and reduce racking of the beam.

i hope the information is helpful
 
I like the Jack up top type , I've seen to many of the others twist and blow parts a cross the shop. Wouldn't have happened but YA get the ,, I know what I'm doing ,,,, YUPP he didn't take a snap ring out , or it had a shoulder they didn't see. Don't get me wrong the up top can bend the bars and blow too. But it seems they others just wobble too much. The Jack part ....
 
One consideration for me is would the jack above be air assist or something. I'm short, with back and shoulder problems which makes it hard to reach to far up. My other though is how rigid is the one above under full force is something cocks to the side a little.
 
If you go with air or electric operated jack I advise installing a gauge so you know how much pressure you are applying.
I have the thought of putting gibs on the slide to keep it from twisting, seems like it would help but I haven't tried it.
 
I've used both of the designs and neither is as good as I guess you would call it the direct ram style. Tony Foale on Homemadetools.net did a real interesting thing, taking a common bottle Jack and modding it to become inverted to be a direct ram type. Much simpler and less likely to bind like either the over or under design. He has a pretty good write up Here
 
kvt said:
One consideration for me is would the jack above be air assist or something. I'm short, with back and shoulder problems which makes it hard to reach to far up. My other though is how rigid is the one above under full force is something cocks to the side a little.
Click to expand...

On the tall 50t press I recall, a rope from the lever came down to a comfortable height. Under pressure
a heavy mount plate pushes hard against the underside of that top girder, and no slippage was likely.
With a two-stage pump, or an 'intensifier', you get
a second pressure stage that engages after things snug up. Pumping by hand is easy enough.

And, of course, there are electric hydraulic pumps for mass production.
Keeping your pressed items from doing
the high-speed-collapse-with-shrapnel is up to the operator.
 
Wow, Tony Foale! I have his moto chassis book. I am in the same bind as Susan, in SF with a tiny shop, but will need a press.
 
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