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Home Built Power Hammer Advice Needed

Dustin D Ehli

Dustin D Ehli

Subscriber
Want to look into building a hammer. Looking at the pivoting leaf spring design cause allows low mounting of the crankshaft and motor.
I have a friend who works in a fab shop so can get deal on all steel and plasma cutting of crank disk etc.
Thinking I beam frame with solid bar all the way to the floor as the bottom die holder, ram connected to the spring on top. Opposite side connected to the crank with a turnbuckle for easy ram adjustment

What I'd like advise on is good working stroke? And if I shoot for 50 ish pound ram what kind of spring pack should I use, trailer springs are shorter than car springs and that would be good I'd think, but what rating.
And what kind of ram guide would be easy to make but keep the die aligned. Greased shaft inside DOM would be easy but wouldn't stop die rotation and that wouldn't work.

Would probably use spare tire drive cause easy and cheap

Ideas welcome. Thanks
 
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dalmatiangirl61

Subscriber
Re: Home built Power hammer advise needed

The one homebuilt power hammer I've seen up close had a square ram inside of heavy wall square tubing, and used delrin sliders that could be adjusted for wear.
 
Dustin D Ehli

Dustin D Ehli

Subscriber
Re: Home built Power hammer advise needed

I was thinking something along that line, using ultra high molecular weight poly
 
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DBH

New member
Most home built hammers are built way to light! Before you build a hammer look at commercially made hammers similar to what you want to build. Most are made of cast iron & they used that material for a reason, to add MASS to the hammer. If you want to save money or just want to build one for the fun of it, go for it. But you can find vintage & some newer hammers at not to bad of prices I would go for it because many times it just dosen't pay to re invent the wheel.

Dave H.
 
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Joel Sanderson

New member
Dustin, do you have Pounding Out the Profits? If not, I recommend it. You'll get ideas from it, for sure.

I've thought that if I were to make a hammer, I'd have most of it cast. It's not all that crazy expensive if you find the right foundry. You'd basically make a wooden hammer and then have the parts cast; machine them, fit them, and you'd be good to go. It'd give you the mass that's just awfully hard to get by fabricating. Now, I haven't done it, and I'm sure there's a lot more to it than that of course, but I bet it'd work. Once you had the patterns, you could have more than one cast, then sell the ones you didn't use to pay for the one you kept! A free power hammer! (Just add labor.)

Do you see any punch presses up your way? They're usually pretty cheap. That makes a very useful forging machine. It's not the same as a hammer, but it'll do anything a hammer can do, and it'll do some things easier than a hammer can do. Maybe I've said this before, I dunno.
 
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Pete Spaco

New member
Re: Home Built Power Hammer Advice Needed/Punch Press?

"Do you see any punch presses up your way? They're usually pretty cheap. That makes a very useful forging machine. It's not the same as a hammer, but it'll do anything a hammer can do, and it'll do some things easier than a hammer can do. Maybe I've said this before, I dunno."

I have seen many punch presses, but I have only used one for "forging". I really wouldn't call it "forging", though. As far as I know, they don't have any springyness in their rams. You set them for a fixed stroke length and that's it.
The issue then, is:
Assume you want to draw a one inch square bar down to 1/2". Where do you set the ram? If you set it at 1/2", it's got to do that in one blow, OR ELSE!
Also, from what I know, a punch press is usually a one-hit device, not a continuous operation.
Sure, you can find pre-OSHA presses around but, as a friend of mine often says: "The only job that a punch press has is to remove your fingers."

Some years ago, we used one for several days to incise the veins in a couple of hundred 16 gauge grape leaves using a fairly sharp fuller as the tool. By cheating all the safety features and reworking the clutch, we were able to get it to make continuous foot controlled strokes at about one per second. But you had better get your work in the right place for the next stroke and you better not have a hand in a pinch position. I'd never do that again.

Pete Stanaitis
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Joel Sanderson

New member
"As far as I know, they don't have any springyness in their rams. You set them for a fixed stroke length and that's it."

Exactly! And that's their advantage over a hammer--in many situations. :)
 
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Pete Spaco

New member
Joel:

re: "And that's their advantage over a hammer--in many situations."

And what might some of those situations be?

Pete Stanaitis
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Joel Sanderson

New member
"And what might some of those situations be?"

A toggle press is more efficient most any time you're forging something where constancy is important and the stock remains the same: forming tendons, off setting, side setting, texturing stock, upsetting, heading, punching holes, cutting, shearing, lining, bending to a controlled form, raising, and so on. That list covers a lot of operations, and I'm sure there're more that I'm not pulling off the top of my head.

I don't want to hijack your thread, Dustin, but maybe this'll help you understand that a press is as useful as a hammer. There's a reason why presses displaced hammers in industry, and it certainly is not because presses are limited. Again, a press can do anything a hammer can do--anything. Some operations are easier with a press; some are more awkward, but there's nothing a hammer can do that a press cannot. I think we've talked about this before if I remember right, Dustin, so please excuse me for being repetitive.
 
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Pete Spaco

New member
Toggle Press and Punch Press are two different animals.
We were NOT talking about toggle presses.

Pete Stanaitis
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Heins

Subscriber
Joel, how much pressure would it take with a press to flatten a blade like this if everything was cut off it that is welded onto it, not counting the part the cutting edge is bolted to it. It is 3/4" thick. If the blade is red hot and press on it about each foot.
 

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Joel Sanderson

New member
Heins, I really can't answer that. That's not the kind of work I do. If you're serious about knowing the answer, you'd need to find out the alloy, run the math and so on.

Pete, I've always understood they're different names for basically the same type of machine: toggle press, knuckle press, horn press, crank press, OBI, punch press--they're all names for presses of different configurations that work on the same principle, which is a crank with a solid link to the ram which cycles in a fixed stroke. Have you heard otherwise? Names might vary regionally too, I dunno.
 
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