The Stovebolt Site Forums The Shop Area The Tool Chest hydrolic press

Well a few years back I built a press using stuff I had laying around.,electric motor driving a pump.The pump put's out 2000 lbs.I used a 2" ram,9" stroke.Well as far as I figure it's only at 4000 lbs at the ram.2000 lbs per square inch equals 4000 with the 2 inch ram?
I've pressed some pretty stuck stuff and it seem's to work great but I'd like to up it a bit.I'm thinking of a 6 to 9 inch ram.Any thought's? Or is my math wrong?Tom

Tom,

PiR2 is the formula for the piston surface. I got 6.2832 sq inches times 2000 psi. This equals 12,566 lbs of oink! I'm not a math major so this might be defective.

That's a respectable amount of push for a home shop press.

Stuart

Maybe things changed by when I was in school PI was 3.14, the radius of a 2" ram is 1" 1 squared is still one times PI = 3.14 times 2000 = 6280 PSI. I changed my major from pre engineering to accounting and pre law. Maybe it was because I was dumb. And I got my degree over 40 years ago. Lots of brain cells have died off since then.

Thank's for the replies guy's.But I'm not anywhere near a math whiz,So I'm either at 6.280 lbs now or 12,566.hmmmI'd like to get 20.000 lbs out of it.It's built out of 2x4 tube steel,heavy wall.reinforced it up top with 4 inch channel and mounted the pump and tank up top out of the way.1 inch pin's holding the deck.I may be going to the storage building today and get a pic.Tom

by 2" ram do you mean the piston bore size [cylinder] or the rod? Force=Pressure X Area of the piston

at 30,000# [2000psi on two 5" cylinders] I bow the uprights on strongbacked 4x12 I beam, 2x4 tube might kill someone at 20,000 ....

Bill

HEY....1 X 1 doesn't' equal 2...sheesh, I told you I was dumber than a post! Sorry grub, Crenwelge is right.

Stuart

I built this one out of 4" Channel. The 12 ton bottle just sits there with a pocket for the bottle's ram to center it. The bottle can be just pulled out and a 20 T set in its place if there was ever a need. The ram for the press, below the bottle is in two pieces. The 1" piece can be removed and push with the larger 1 9/16" section. Only the table is welded and is supported by two 5/8" pins on both sides. The rest is bolted with 9/16" grade 8 bolts and with the 12 T has not failed me.
Press

Getting back to the original question, the length of the ram has nothing to do pushing power. If you are talking about a 6" to 9" diameter ram, you will have to rebuild your whole contraption because you will be dealing with 56,000 and 127,000 lbs of pressure. When you square the radius, you get up there in a hurry. We have a 100 ton press in our shop and it so big it takes a fork lift to move it and there is nothing on a pickup that requires that kind of press.

Looks similar to mine Richard. I always wanted to mount a cylinder in the top and use the portable Enerpac electric hydraulic pump that I have under the bench. Just have a hard time parting with a couple hundred bucks for a threaded cylinder and mount.
Here’s my 20ton 4” frame floor press;
http://rides.webshots.com/photo/2907021760098611668ZTwdFf

and the 1.5ton 3” frame bench press;
http://rides.webshots.com/photo/2411354440098611668rbYRFs

Denny Graham
Sandwich, IL

You do nice fab work.Two weeks ago I was able to get a tour of an old machine shop with the shafts and drive belts in the ceiling (circa 1900).They had a "home built" 250 ton press with a brass pressure gauge, in the back of the shop.With 500,000 PSI,I could really get into trouble!!

A very easy piece of equip. to weld up,in the shop.A few pieces of channel iron a good drill press to make some large holes for table height adjustment plus a hydraulic bottle jack.And Viola,youve got a hydraulic press.

http://good-times.webshots.com/photo/2419730080104384290kZpxHT
http://good-times.webshots.com/photo/2530423300104384290qNFniM
Couple of pics I hope,new to the pic deal
Ok so I'm probbally going with a 3-4" ram as soon as I get one.I can install some bracing on top(gussets) Like I said just want to up it a bit,not overkill.

I may not be an engineer, but I have seen and used a number of different hydraulic presses, and I don't think you want to go with a larger ram. The frame looks like it may or may not just be enough for the setup you have now.

One shop I worked at someone was pressing something supported in V-blocks, one of the blocks exploded, that was not a good picture.
There is a lot of force involved, and if something fails it can be quite dangerous, don't take any unnecessary chances. You could buy a really nice commercially built press for less than a hospital bill..

Grigg

If you go look at some of the cheap chinese crap on the market you will see that they supply the presses with cast iron blocks. Those cheap cast blocks will split apart like glass before they will bend.

If the one you built in the first place works for what you do, why mess with it. If you more power, get a little bit bigger ram, but then you will need a stronger frame. The presses with bottle jacks work fine, but they are slow, especially when you get into a 20 ton jack. Our 100 ton press has 3 speeds, either air over hydraulic or manual pumping. Several years ago we built an oil filter crusher out of a pump similar to what you have. We crushed a filter with our hydraulic press to figure out how many tons it took to crush a filter and then bought a ram with the proper diameter and stroke. It works like the new $2000 kind with only a $200 ram out of pocket.

Agree wit ya Grigg, the first thing that jumped right out at me when I heard talk of a bigger cylinder was that three inch channel at the top. Won't take much more in that wide of a span than what you already have on it. Of course you could always bring gussets down in the corners but it would be just as easy to go to a four inch channel and have done with it.
Denny Graham
Sandwhich, IL

Yup 4 inch channel it will be then,and a plate.I've decided to go with the 3 inch ram so it'll be better than it is now,but not to dangerous,I know, I've seen thing's come out of presses,and they fly out quick!Safety first!

i dunno about you guys but we have a huge one, 4'' piston with 24,000 lbs capacity, i ought to put some pics up, its worked flawlessly since my dad built it back in the 80's

Yeah young guns,put a pic up!