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Adding hydraulic foot control to electric hydraulic unit / press

Sincerd

Aluminum
Joined
Jul 22, 2023
I'm not sure what it is about hydraulics, but it's got to be one of the hardest topics to find information about. Very few forum post, mostpy about adding air powered pumps to existing presses.

Im Planning on building probably 100 ton press frame and want an actual 50T dual acting threaded ram.

I'm stuck between buying and building the hydraulic power unit. I want electric hydraulic. If I buy, I'm likely to go into 10,000 PSI and one of the units comes with a foot switch for about $1500 from temco. But its lacking in capacity and foot switch looks like it belongs on a cheap sewing machine. I have a old enerpac hush pup but looking at options for foot pedals and changing out the valve, is probably going to be triple what the unit is worth.

On to building, I could run 3,000 PSI and get a 6-7" Ram to get 50t. Thats going to make way more difficult on smaller parts. Plus I can't find any information on adding a foot control. Is it easier to do it electronically? Im waning foot press to lower, foot release to raise ram. But with dual acting, wouldn't it need to activate the valve to affect flow like this? Why does this seem so uncommon? Seems like this would be the most common use for hydraulic power units on shop tools.
 
I'm not sure what it is about hydraulics, but it's got to be one of the hardest topics to find information about. Very few forum post, mostpy about adding air powered pumps to existing presses.

Im Planning on building probably 100 ton press frame and want an actual 50T dual acting threaded ram.

I'm stuck between buying and building the hydraulic power unit. I want electric hydraulic. If I buy, I'm likely to go into 10,000 PSI and one of the units comes with a foot switch for about $1500 from temco. But its lacking in capacity and foot switch looks like it belongs on a cheap sewing machine. I have a old enerpac hush pup but looking at options for foot pedals and changing out the valve, is probably going to be triple what the unit is worth.

On to building, I could run 3,000 PSI and get a 6-7" Ram to get 50t. Thats going to make way more difficult on smaller parts. Plus I can't find any information on adding a foot control. Is it easier to do it electronically? Im waning foot press to lower, foot release to raise ram. But with dual acting, wouldn't it need to activate the valve to affect flow like this? Why does this seem so uncommon? Seems like this would be the most common use for hydraulic power units on shop tools.
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one of these....
 
Manual valves for controlling 10,000 psi flows are a pretty difficult problem because the friction from any effective seal will be very high. At my work, we have many manual hydraulic isolation ball valves and occasionally we break the handles when trying to close or open them under pressure. An electrically controlled pump feeding the cylinder through a check valve, and a needle valve to bleed it back down are typical for this sort of application. Make a rocker switch that energizes the pump when pressed and opens the bleed valve when released. If it were mine, I would have a "dead" center that allowed the pressure to be held, and when pressed with the heel it would vent.
 
Manual valves for controlling 10,000 psi flows are a pretty difficult problem because the friction from any effective seal will be very high. At my work, we have many manual hydraulic isolation ball valves and occasionally we break the handles when trying to close or open them under pressure. An electrically controlled pump feeding the cylinder through a check valve, and a needle valve to bleed it back down are typical for this sort of application. Make a rocker switch that energizes the pump when pressed and opens the bleed valve when released. If it were mine, I would have a "dead" center that allowed the pressure to be held, and when pressed with the heel it would vent.
Would that work with double acting cylinder? Maybe my ignorance but it sounds like single.
 
I used to make presses like that ....I never went above 3,000psi as thats where cheap components are OK..........I designed a very simple foot valve ,that was basically forcing a tapered rod into an orifice ...very simple .....and with a standard two way spool valve to controll direction..........Since every press was pre ordered and specced by the buyer ,for a bit extra ,there could be a 'tight spool' valve that would hold pressure for at least 2 hrs..........the only slightly tricky thing is air buildup in a two way cylinder ...you need to work out some way of bleeding both ends without tipping the press on its side............although some presses were meant to be tipped and worked either upright or on the horizontal.
 
I built a large double acting press for forging and riveting from 10,000 psi enerpac components 20 odd years ago, and found it much easier to electricaly swicth the pump, than try to switch or valve the hydraulic lines. Enerpac aint cheap, but its quality, parts are available and the selection of components is huge.
 
At my old company, we had a large press at work, maybe 50 tons, that was electric powered with a foot control. The problem with such presses is they give no real operator feedback....unlike a manually operated press. So a couple dinks were running it and failed to notice they had a binding situation with what they were pressing. Won't go? Give it some more pedal....

When the whole mess finally let loose, a chunk of steel hit one of the dinks in the chest. It didn't kill him, but it fucked him up big time....a couple months in the hospital and all the usual lawsuits.

So...the company finally settled the lawsuit and part of it was he got to keep his job...he was useless before the accident and now he's even more useless...basically paid to sit around all day riding the shop cart and occupying a job that could be held by someone who needed a job.

One day I was walking through the shop with one of our older mechanical engineers and we saw the dink riding around....the ME commented, "It would have been better for all if he had just gone ahead and died...' lol
 
Very true thats its easy to bust stuff ........even with a hand pump ,there is no feel with a 100 ton press..........this isnt a problem straightening heavy shafts and bar ,but any mechanical work ,you need to be very careful not to bust costly parts..............One disaster Ive seen is pushing dry liners from cylinder blocks .......dont bust the block .
 
10,000 psi? A lot of the CAT, Hitachi etc earth moving equipment have there relief valves set to 5,000 psi maximum on machines weighing 100 - over 500 tons. I've had a few hoses blow around that 5k psi mark, and trust me, you don't want to be anywhere close if it were to happen. High pressure oil injected into your self is apparently quite painful when it doesn't kill you. Even at 5k, they also use a much lower pressure secondary hydraulic pilot circuit on the control valve side to actuate the main high pressure valves. In simple terms, it all works a bit like an electrical solenoid except it's mechanical / hydraulic and using fluid to do roughly the same thing.

So that vastly reduces the pressures at the operator controls, and a secondary benefit is there's no 5,000 psi inside the cab or even close to the operator. So are you going to be using the much more complex and expensive pilot control circuit. Because I doubt there's many or maybe any controls around that can handle 10k psi without it. I sure don't know much about hydraulics, but there's not a hope I'd ever try building a system that's anywhere near 10k unless I knew someone in the hydraulic design & engineering industry. And however you do it 10k psi isn't going to be cheap. Getting that pressure is just one of the simpler issues. Try pricing hydraulic hose and main valves that are rated for your 10k and you'll start to rethink this. Because right now it's pretty obvious you don't know nearly enough. Yeah there's probably many here who could build one with the proper safely margins, but they also know way more than I do.
 
Pressures up to 6,000 psi are common in Euro machines ...truck cranes a common example ........but components are way more costly than standard 3000 psi ,which is everything from hoses to cylinder packings................however by simple arithmetic if a ram develops 50 tons at 3000psi, it will develop 100 tons at 6,000psi.
 
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10,000 psi? A lot of the CAT, Hitachi etc earth moving equipment have there relief valves set to 5,000 psi maximum on machines weighing 100 - over 500 tons. I've had a few hoses blow around that 5k psi mark, and trust me, you don't want to be anywhere close if it were to happen. High pressure oil injected into your self is apparently quite painful when it doesn't kill you. Even at 5k, they also use a much lower pressure secondary hydraulic pilot circuit on the control valve side to actuate the main high pressure valves. In simple terms, it all works a bit like an electrical solenoid except it's mechanical / hydraulic and using fluid to do roughly the same thing.

So that vastly reduces the pressures at the operator controls, and a secondary benefit is there's no 5,000 psi inside the cab or even close to the operator. So are you going to be using the much more complex and expensive pilot control circuit. Because I doubt there's many or maybe any controls around that can handle 10k psi without it. I sure don't know much about hydraulics, but there's not a hope I'd ever try building a system that's anywhere near 10k unless I knew someone in the hydraulic design & engineering industry. And however you do it 10k psi isn't going to be cheap. Getting that pressure is just one of the simpler issues. Try pricing hydraulic hose and main valves that are rated for your 10k and you'll start to rethink this. Because right now it's pretty obvious you don't know nearly enough. Yeah there's probably many here who could build one with the proper safely margins, but they also know way more than I do.
If I was building, I would agree with you but it looks like enerpac stuff is almost all 10k psi. I assume you need quality fittings and hoses but I can't see them causing too many injuries without enerpac being sued out of business.

The pump comes as a pre-built unit designed specifically to use with their cylinders. I don't know maybe it is a hazard but they've been selling these units forever. The one i have is from the mid 90s. Seems like if it was as dangerous as you say, they probably wouldn't still make them. Or maybe I'm just ignorant and they kill people all the time. Who knows?

All the air/hydraulic stuff is also mostly 10k
 
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Ive had hoses blow off fitting s with 10,000 psi Porta-Powers ......fluid loss was negligible ..........pressure was probably well in excess too,as the portable pullers and rams are often abused to get that little bit extra to break loose a gear or sprocket.
 
Solenoid 12V 02-332169 for Eaton Vickers Hydraulic Solenoid Directional Valve
That looks exactly like what I need but a 120 volt which they do offer. That will help a lot now I got to research how to incorporate it. Which again I'm not finding much online, but I'll get there eventually.
 








 
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