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I Forge Iron

HELP: forging presses


Ross Moffett

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Ross. The ram plate and guides are probably the trickiest part of something like this. Your latest drawing is a lot more rigid than the ones before but it's getting so just welding it up will rack it as the welds cool.

Were I doing this I'd use two lengths of channel iron, say(C 8 x 18.75) 8" x 18.75 lb./foot. Space them so the guides weld directly to the ends. The channels are oriented web to web,not touching but flanges out. This will give it the most resistance to twisting in there is uneven resistance. Say you're using kiss blocks and one gets knocked off the anvil plate so the ram is stopped off center. Yes?

The ram pins in a sleeve that is a spacer between the channels about 1/3 of the way down from the top. The gap between the webs shouldn't be much wider than the end coupler of the ram, a couple washers gap, you want a LITTLE room to flex but not enough to let the pin bend or shear. THAT dimension dictates the spacing between the webs of the channels, I'd box it to there was an 8" deep box channel with nearly 1/2" thick webs and four 2.5" flanges. Stitch weld a piece of 1/2" strap stock to the web between and flush with the flanges. This is an incredibly strong and rigid structure with far less chance of racking as the welds pull, cooling.

Build your guides so they span between the press frame in a single piece, say 1/2" x  8" strap stock welded between the ends of the boxed channel. You can bolt the guide together at this point, the girder that spans the guides isn't going to flex so the guides are only going to guide it, NOT try and hold it. Does that make sense?

A version of this arrangement will be stronger, more rigid, lighter and more soundly engineered.

And no, I don't have the dimensions and weights of steel in my head, well if I do I can't find them. So I looked here for the details, this is a terrific  reference site when you're building. I have my old engineer's steel book up stairs somewhere but I was sitting at my comp. The link is to THE page I referenced to write this but that's not all they have for you. http://www.engineeringtoolbox.com/american-standard-steel-channels-d_1321.html

Frosty The Lucky.

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Ross. The ram plate and guides are probably the trickiest part of something like this. Your latest drawing is a lot more rigid than the ones before but it's getting so just welding it up will rack it as the welds cool.

Were I doing this I'd use two lengths of channel iron, say(C 8 x 18.75) 8" x 18.75 lb./foot. Space them so the guides weld directly to the ends. The channels are oriented web to web,not touching but flanges out. This will give it the most resistance to twisting in there is uneven resistance. Say you're using kiss blocks and one gets knocked off the anvil plate so the ram is stopped off center. Yes?

The ram pins in a sleeve that is a spacer between the channels about 1/3 of the way down from the top. The gap between the webs shouldn't be much wider than the end coupler of the ram, a couple washers gap, you want a LITTLE room to flex but not enough to let the pin bend or shear. THAT dimension dictates the spacing between the webs of the channels, I'd box it to there was an 8" deep box channel with nearly 1/2" thick webs and four 2.5" flanges. Stitch weld a piece of 1/2" strap stock to the web between and flush with the flanges. This is an incredibly strong and rigid structure with far less chance of racking as the welds pull, cooling.

Build your guides so they span between the press frame in a single piece, say 1/2" x  8" strap stock welded between the ends of the boxed channel. You can bolt the guide together at this point, the girder that spans the guides isn't going to flex so the guides are only going to guide it, NOT try and hold it. Does that make sense?

A version of this arrangement will be stronger, more rigid, lighter and more soundly engineered.

And no, I don't have the dimensions and weights of steel in my head, well if I do I can't find them. So I looked here for the details, this is a terrific  reference site when you're building. I have my old engineer's steel book up stairs somewhere but I was sitting at my comp. The link is to THE page I referenced to write this but that's not all they have for you. http://www.engineeringtoolbox.com/american-standard-steel-channels-d_1321.html

Frosty The Lucky.

Hi Frosty.

Thanks for the advice, do you have by any chance an example?

I've understood most of what you are saying but an example would help, am I just being thickheaded?

Ross.

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This design is based on the "Build Your Own Hydraulic Forging Press" By Jim Batson, -  Hydraulic press plans as far as the hydraulics, I designed the frame based on what I had laying around the shop at the time. Tube uprights 4"x4"x1/4" with 1"x4" plates welded as shown. Frame is on casters for ease of moving where needed.

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Bubba

How to figure out the power of a Hydraulic Cylinder.

Pi x R2 gives you surface area. Pump pressure x cylinder surface area = Power of Ram . ie for a 4" cylinder. 3.1416x2x2=12.5664 sq. in. 3000 psi pump x 12.5664 = 37699 lbs/sq.in. or 18.8496 Ton/sq.in.

If the Contact surface of the Ram is a triangle and measures 1/10 of a sq.in. The Force on the edge of the wedge will be 10x18.8496 Ton/sq.in. = 188,496 Ton/sq.in

Hydraulic's is mathmatics. Do your Math.

Neil

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I got 16.8 tons 2x2x3.142=12.568 sq" x3000 = 37704 lb + 2240 (lbs in a ton) = 16.832 Tons. While yes using the working area of the tooling may be useful I feel its a bit meaningless if you had a sharp pin the force could be 100000 tons though it seems its comon practice in America to quote the psi generated at the working edge, A friend I know at a local hydraulics place had someone turn up with a cheap log splitter they had brought from a local hard ware shop it was american made and it quoted a figure of so many psi force but that was at the cutting edge it had little actual power and the guy got his money back Cheers Beaver

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Good Morning Beaver,

Yes, you are correct. There is a short Ton, a long Ton and a metric Tonne. All are different.

The point I was trying to make was, the actual power at the working surface is not a constant. If the Hydraulic Cylinder is turned upside down, you must figure the diameter of the Ram Rod and remove that from your surface area of the Cylinder piston. Mathmatics is a fun game. I always tease my Blacksmith Class when we are figuring out how much material for an eye, Pi x D. Cake R square, Pi R round. Sometimes you just have to be there!!LOL

Enjoy the journey!!

Neil

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Good Morning Beaver,

Yes, you are correct. There is a short Ton, a long Ton and a metric Tonne. All are different.

The point I was trying to make was, the actual power at the working surface is not a constant. If the Hydraulic Cylinder is turned upside down, you must figure the diameter of the Ram Rod and remove that from your surface area of the Cylinder piston. Mathmatics is a fun game. I always tease my Blacksmith Class when we are figuring out how much material for an eye, Pi x D. Cake R square, Pi R round. Sometimes you just have to be there!!LOL

Enjoy the journey!!

Neil

Hi Neil

The only time the ram spear size makes any difference is on the retracting force and and speed, It doesnt matter which way the ram is put the extenstion force is the same. If the ram spear is taken to the extreme and made the same as the bore it still has the same force it just becomes a single acting ram. Cheers Beaver

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Ross, here is a pic of how I did mine.

There is removable spacers on top of the press head in the picture.

IMG_20170928_091700028.jpg

Hi Jeremy,

Sorry for not replying sooner, but I'ver not had internet access for the last few days!

Nice press you have there.

Now I'm back home I can start looking what scrap I have available, then make a new design.

Ross.

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