What's new
What's new

Engineering Question: Building a 35ton Hydraulic Press

GordoB

Plastic
Joined
May 18, 2011
Location
Sydney, Australia
Hello all out there and a special hello to any engineers (mechanical/structural) as well

I am planning to build a 35ton Hydraulic press in the coming week to satisfy my desire to make damascus steel blades. I have already bought the hydraulic ram and powerpack (thanks fleabay) so these is my limiting factor for the build.

I am looking to build a "H-Frame" type press out of Structural channel with dimensions 200x75mm. I believe this will give me enough strength to cope with the forces involved and will allow me to bolt the Ram onto the top crossbar (it has been designed to do this already).

My Problem lies with the Joining of the Channel steel. Im certified in welding, so nothing scares me there. but i would ideally like to be able to unbolt the frame for portability. i have a fair idea of how im going to weld the bolting plates onto the frame, but as to the bolt sizes im at a loss. I was thinking about using 10 or 12 mm bolts to join the beams.

Can anyone see any potential issues with my logic? (potential for bolts shearing/ beams bending etc)

Thanks,
Gordo B
 
If there is a commercially available frame from a trusted maker similar to what you propose then use it for an example. Often the first step in any engineering design is to understand what has been done before.

If nothing exists then please post a sketch of what you propose. I'm sure that will generate lots of suggestions.
 
During many years worked in automotive machine shops, pressing axle bearings and the like, the sweetest press to use was the Nugier 40 ton, 2 speed, hand operated pump model. The handle was a steel bar about 4' long that slides in it's holder and it's mounted at shoulder height. Center the bar and it counterbalances itself so it's very fast and easy to pump in high speed. When it contacts the work, twist the knob to slow speed, pull the bar out to full length and HANG on it if needed. You could take up several inches of slack, shift to low speed, and pop the bearing loose in a few seconds. The entire H frame is bolted together and the main table rests on 2 pins (1" maybe?) at either side through the frame. Built in winch & cables allowed changing table height in 30 seconds too.
Look at the Nugier site, they have pdf breakdown pics of the frame on the 40 & 50 ton presses. The 50 ton picture has list of the parts with bolt sizes etc. Build close to that and consider it a little overkill maybe. Good Luck!
 
I am asumming that you are using the two 200mm x 75mm with the long side being vertical as the rails for the hydraulics and the same for the press rail. If that is the case, I would use at least 16mm class 10.9 bolts two bolts per side per rail. Torque each bolt to 280 Nm.


The 12mm class 10.9 is too close for comfort for a home built unit to make me feel safe.


At the foot portion the 10mm to 12mm would be just fine.
 
The Nugier press looks sweet(thanks, John Dunn). They actually have a website with drawings (!):

Index of /drawings/HAND/H40-H50

Looks like your idea for building a press that will break down is doable.

Here, for example, below is a 50 ton frame. The one thing I don't like about their press is the cross-bar. I like the design where the cross-bar is channel, with welded channel cross-bars. It would seem to be to be more rigid. Then again, note the cool full box frame on each side of the cross-piece. Very nice. Anyway, Nugier is using three 3/4 bolts per corner, total 12, to fasten the head piece to the side rails. How's that for help!?
frame50tons.jpg
 
Gordo, I can't add anything to what has already said. My press is a bit smaller at 25 Ton with 5/8 bolts and 1" pins.

Curious, are you meaning to impress a slot into the steel, or forge weld it. As to the later, the press is slow even with a 2 speed electric motor as I have. Just interested to learn what is the process.
 
Most smithys make "Damascus steel" using a hammer or power hammer. Don't know why you'ld try it with a press. Doesn't seem to me that 35 tons would be enough.
 
35 tons seems a bit light for what I think that you are doing, but...

For many years, I built a line of bench-top hyd presses for shaping and forming jewelry (20 and 50 tons). Having made hundreds of them, I feel comfortable in making some informed suggestions.

General considerations:
Every thousandth of movement in frame flex is wasted energy that is not going into the forming of the metal. Frame flex is your worst enemy.

For your specific application, I would make the horizontals as short as possible, as they tend to be the weakest element. For example, 6 to 8 inches between the uprights would provide room for the ram, and plenty of room for the blade.

The purpose of the bolts should be for nothing more than holding the elements together. They should not be used in a shear mode. Weld bolsters above and below the horizontals to take the load.

The Nugier press is an excellent piece of equipment, but is designed to handle everything that comes into the shop, therefore it is much larger than your specific application, and the frame will do some serious flexing when pushed to the max. If you don't believe me, just put a dial indicator in the middle of the frame and see how much it moves (making sure that you have the base attached to something off to one side).

Lee (they saw guy).
 
I have made a small table top forging press for a knife maker using a press that I make for the jewelry industry there is a video on you tube of it in action under mini forging press or under potter usa. I used an air over hydraulic jack from the dreaded harbor freight. It works fine and you will be able to forge weld damascus steel with it. You can use a better hydraulic system such as an enerpac, that is what I have been using on the 50 ton forging presses that I have been selling. My presses are not made with structural steel they are cut from plate to minimize the the welding and potetial failure. I have made them up to 100 tons using this method.
 
How are you going to use a press to make Damascus? It will cool off below welding before you can squeeze it. The press jaws will be a heat sink. Don't you need to hammer it?
 
kpotter,

That is a nice looking press you have there! Clean and sturdy design! :cheers:

I watched your video and another one where the fellow was doing some hot forging on his model. Made it look like he was working with clay.
 
Hi All,

Thankyou so much for your replies. When i loaded up this forum i was a little overwhelmed at the amount of interest in the Topic.

Bosleyjr, This is exactly what i was thinking in my head. this drawing has now just put it on paper for me.

gwilson, Damascus can be made using the press. I have had some experience doing so using only a 20ton press and it made life extremely easy

Thanks again
 
GordoB, if you have all the required materials to hand, making your own hydraulic press makes sense, and you could do no worse than go for a wander through Hare & Forbes to see how their offerings are constructed.

If you have to buy all the components, I suggest it would be more economical to just buy a Hafco item, which do come in bolt together form. Around $1000 will get you a 50 tonne press which is probably around 35 real world tonnnes.
 
Hello GordoB
I'm not an engineer so I speak to you in layman's terms from my own experience. The 2 presses referred to above are missing something. I know that one is just a plan for the frame, but the other one looks to be completed. They are missing a way to raise & lower the bed. I built a 50 ton press. The bed is 5' wide, made out of the heaviest 12" channel. Each piece weighs 150 Lbs. The whole bed weighs over 300 Lbs. Your 35 ton will be lighter, but still there's now way you would be able to raise & lower it by hand by yourself. I used a hand winch & cable to each end of the bed on mine. You might want to add that to your plan.
 
kpotter,

I agree with others regarding your very attractive, and obviously functional press design (the execution looks very nice, too!).

You have your own video style, and it comes across as expert and credible, but golly you surely could brag a little bit more! :D

Very nice.
 
I am glade you like the press. Most of my customers are middle age women who are hobbiests. I have sold a press to the canadian mint they use it for aligning dies. I want to make a small portable iron worker that would mount on a bumper of a big service truck.
 








 
Back
Top