Hydraulic press

[Gordon Maney]

When I was an automotive instructor I had a hydraulic press in my shop. I recall it being a 20 ton; it was a Dake brand press, I think.

I am considering building one and am undecided on capacity. I am wondering what you might have as a press in your shop, and what capacity you have, what capacity you wish you had.

As an aside, I once saw a huge mechanical press, based upon a huge screw, and a wheel you turned to rotate it that was three feet in diameter. There was a lever that provided what amounted to compound leverage against the perimeter of the wheel. A marvelous beast, it must have weighed 1,500 pounds or more.

....so, what are your thoughts on the press?

[Russell Colvin]

press

Gordon,
I have a fly press that I use for forging. I also have a straightening press with a cylinder that rolls from one end to the other.

[Gordon Maney]

What is a fly press?

The rolling cylinder is on a typical H-frame press made of heavy channel?

[HWooldridge]

Gordon,

A fly press is similar to what you described - it's an arch frame with a very coarse, fast thread screw running vertically thru the center. There is a large spoked wheel attached to the screw with a weight hanging from an arm of the wheel. For forging, the work or dies are put below the screw and the wheel spun. The momentum from the weight and wheel propel the ram with sufficient force to move metal. The wheel is often "bounced" to perform squeezing while the work is manipulated.

I have a 50 ton Dake. It is a manual unit with H-frame, i.e., the horizontal beam is adjustable for height. I use it quite often and there are times when nothing else will budge a part except hydraulic pressure. It also allows a lot of control.

Presses are pretty low-tech so you could either make one or pick one up cheaply if you watch estate sales or auctions. Check out Northern Hydraulics or one of the other machinery dealers.

[Gordon Maney]

That is interesting. The one I described is the only one I had ever seen. I would like to have one of those, too.

Does your 50 ton press have a hand pump? In my experience, I like such a process to be able to give me some feedback, unlike a motor driven pump. Though, with a gauge and what thie hydraulics fellow called a feathering valve, you could approximate that.

When I was a truck mechanic, I remember some times when the only way we could get king pins out of the axle beam on a big truck like a ready mix truck, was to use this big press we had. It was kind of fun, actually.

....watching that big ram move slowly down to the part, things do that barely perceptible bit of settling into place, then the cracking, popping sounds and transitioning into..... yes..... motion.

[HWooldridge]

Gordon,

Yes, my Dake has a hand pump and I prefer it for most things because as you stated, it has a "feel" to it. I can hear the frame grunting and squeaking when it gets loaded. However, I do not think I have ever used it to full capacity, because I cannot recall seeing the gauge go above 35 or so tons. Most stuff starts moving around 15 or so - I think that may be why 25 ton units are so popular. I will also say that safety needs to be paramount when using one since a piece under load will fly like a bullet if it kicks out. People who use little scraps of steel, punches or screwdrivers betwixt press and work, scare me to no end. I was in the injection molding business for almost 20 years and it was an everyday occurrence to work with over 1000 tons of hydraulic clamp on some tools. You see very quickly how important it is to have everything SQUARE when using great pressures.

This brings up another good practice for the home mechanic, which is to put a spacer in your bench vise if the work is off-center. A piece of 1/2 stock on the edge of a vise causes great strain if a corresponding spacer is not placed on the opposite corner. Not only does this habit save the vise but allows greater clamping since the vise is square to the work. I have a complete set of homemade spacers from 1/8 to 3/4 in 1/16 increments, which stay in a tray near one of my post vises. Take a piece of stock 3 inches or so long and split it with band or hack saw to about 1 inch. Heat with a torch and spread the legs until the piece will hang in the vise (it will look like a "T" when done). This allows you to drop it in the vise without needing a third arm. A bit OT from your original post but perhaps useful to someone...

[Gordon Maney]

I am bringing this thread back up because it seems possible that there are new people who have had occasion to fabricate or purchase hydraulic presses.

The thread pertaining to late Ram ball joints that are pressed into steering knuckles caused me to think of this again.

One of the neatest, big presses I saw fabricated used the forcing cylinder to raise and lower the main horizontal channels of the H frame to the desired position. It used a motor driven pump, rather than a hand pump.

[Steve G]

I have been thinking about making a press for awhile and have gathered 6" c channel, some 1" thick plates, and a piece of 1 1/2" round stock about 8" long. The pump I'm going to get is a 20 ton air/ hydraulic bottle jack. I would like to put a foot valve on it so I can use both hands to steady the work. Then when the ram comes in contact, I can use the hand pump. I have to decide whether to make a floor or benchtop model. If I make a floor model, I was thinking about using a boat type hand crank winch to raise and lower the height adjustment. I could run the cable through a few pullys if the geometry is correct, but thats the fun in fabricating. Oh, and that jack is on sale at Harbor Freight til March 12th for $70. I know its not going to be a USA model but it will work for the hobby mechanic.

[IAN J]

Hydraulic Bottle Jack modification

I bought a conventional 20Ton hydraulic bottle jack to use on a Hydraulic Press I've made. Does anyone know how to modify a bottle jack so that it can be used inverted in the press? I remember an old friend (now deceased) modified one years ago for his home made press. It had a hydraulic fluid reservoir and pump mounted seperately on the press frame.