Restoring a K.R. Willson, 50 Ton, Hydraulic Press...

[Eddyde]

I am starting a new thread covering the restoration of my newly acquired hydraulic press, to continue story from the thread of how and why I bought it. Here:

Thread 'Pressing Need...'

Nov 11, 2024

Or the confessions of a vintage machine hoarder enthusiast.

This journey started during the "Cigar Fad" of the mid 90's. At the time, I had a partnership in a custom cabinet and millwork shop. One day, my partner, Philippe, brought in a picture of a humidor and said he had a friend who would wanted him to make one for him. The one on the picture was $1,500 but philippe said he could do it for half that, Indeed $750 back then was great money for fairly simple wooden box. Philippe made the humidor, his friend loved it and so did all his friends and more orders started coming. Seeing...

• Eddyde
• forging hydraulic k.r. wilson kr willson krw press vintage
• Replies: 7
• Forum: MEMBERS PROJECTS - POST YOUR PROJECTS HERE!

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I am also moving a couple of posts from that thread here, to avoid redundancy:


I got the electrical reconfigured. It was wired for 440v three phase, the starter was old and not in the correct enclosure so I just bought a new one.
Fortunately, the motor wires weren't too crusty and re-splicing them for 220v was without issue. I did replace the cable between the starter and the motor as it was only 14 gauge, okay perhaps for a 5 hp motor at 440v but not at 220v. I also changed the wire going to the switch as it was pretty crumbly. A "new" power cord and proper plug was added as well.

The control valve & start switch are operated by the same lever. It's kind of a primitive arrangement. A tab welded on the side of the lever actuates a micro-switch attached to the top of the valve housing. When pushed forward the lever simultaneously starts the pump motor and routs the hydraulic fluid to the cylinder, forcing the ram down. Returning the lever to the center, neutral position shuts the pump, the cylinder is locked out and the ram will hold its position. Pulling the lever all the way to the rear, opens the valve, a spring inside the cylinder pushes the ram up and the hydraulic fluid flows back to the reservoir.

One safety problem, the switch is very sensitive and the lever can trip it under its own weight, This was noticed when I first plugged it in and the motor came on! It appears the lever return spring inside the valve block is worn or broken. There had been a "safety" interlock button, that someone had wired in that also needed to be pressed to start the motor, but it was in the opposite side of the machine and required one to have your arms spread, right in from of the press while its operating, not too safe either... Also I will need to have at least one hand free while operating it.

So, I am contemplating solutions. My first thought is to wire a smaller safety interlock button on the end of the lever so it can be pushed at the same time. Of course the lever spring must also be fixed.

Another Idea is to do away with the on-off and have the pump run continuously. Install a modern hydraulic valve that would allow the fluid to cycle through to the reservoir when in the neutral position.

A hybrid of that idea is to install an electrically controlled hydraulic valve. That could open the possibilities of electronic control, like pressing to a set thickness, auto cycle up and down, etc. A foot switch would also be possible.


No good...

Much better...

The wonky lever-switch...

I welcome any other Ideas on how to control this beast!

 

[mattthemuppet2]

I'd go with the motor on/ off controlled by a separate switch, then a two (three?) way hydraulic valve. Ideally one that is proportional, not just on/ off, as it can be a big help to be able to slow down the extension or feather the amount of pressure the press is exerting. Otherwise they can become very efficient ways of breaking things.

 

[Eddyde]

Thanks, that's a very good idea, I'll see what kind of proportional valves are available. One issue I'm finding; the working pressure of the press is 5,100 psi (@50 Tons), and the pump is rated at up to 10,000 psi output. However, it seems many hydraulic components are only rated around 3,500-4,500 psi, the 5,000-10,000 psi rated stuff is harder to find and gets quite expensive.

 

[Eddyde]

Another problem, the cable winch used to raise and lower the table is quite primitive, having no gear reduction and only a simple ratchet paw to prevent a "rapid descent". The force needed to turn the drum was so great it even twisted the square drive boss. Also, I am increasing the table from ¾" to 3" thick, thus adding considerably more weight. I first thought about modifying the winch with a worm gear arrangement, to that end I found a HF, worm gear winch I was going to use for the parts but decided to simply swap the whole winch out.

The original winch:

Dubious connections!

The much safer and more powerful winch installed. I had to make a mounting adapter out of some ⅜" plate steel. Another nice feature is the hex drive makes the winch easy to drive with a cordless drill.

That made hoisting the newly acquired 3" thick table, a breeze...

I still may eventually modify the original winch to a worm geared drive and reinstall it, but this arrangement is more than adequate for now.

Thanks for looking.

 

[markba633csi]

Very nice press Ed. If I ever find myself with a fly head (and arm) I'll know who to call on to do the squishing