Power hammer design Q's

Sam Salvati

Sam Salvati

Joined
Aug 6, 2007
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Power hammer design, the red color coded frame is a frame I got from an old mixer I think, it is all 1/4 by 2 angle iron and a 1/4 thick plate, very sturdy. BTW hehe it won't be painted these colors (well OK MAYBE) I just color coded things so I can print it out and label things accordingly. One thing I did not add to the illustration was a set of springs, tensioned when all done to hold the ram in a just slightly up position so that as with a treadle hammer the force needed to be applied to move the ram will be MUCH less coupled with the mechanical advantage of the actuator being so close to the pivot it should hit much harder than usual with a high BPM rate also and only require a small amount of force. Also, the springs will always keep the ram in an up position. As you can see it is a rusty type spring helve with a tire hammer drive. A bit of help with the color coding, blue is pillow blocks, yellow is the ram and dies, green is the tire and motor, teal is the spring, red is the frame, grey is the anvil and shafting and guides and stuff and the rest is self explainatory(if not just ask). The amount of travel/distance between the dies at maximum open will be about 10 or 12 inches. Comments, critique, suggestions, compliments and loud guffaws welcome. :D





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that is nearly identical to my home built hammer. only difference i see is where you have a pillow block bearing, the friend who built mine just used a steel shaft with a slightly larger dia. steel tube over it on drilled an oiler whole into the tube.
 
Sam, check his page link in his profile. Under the shop photos, I believe there is a pic.

Like the design. Looks like it would do its job well. May have to build one of these some day.

--nathan
 
Oh yeah, DUH me right there in front of my face, thanks Nathan.

You can see where I have replaced the center upright tube connecting tubes with the frame of the old mixer, I have had that frame for quite awhile been dying to use it.
 
Sam, looks good--correct me if i'm way off, but it looks like a tire being driven with an electric motor---using the foot control to determine the contact force with the tire. is the top cross piece a leaf spring (auto or truck)? good luck on this and post when done and hammerin.........azmike
 
sam

i just noticed another difference, i just glanced quickly before, but where your using a tire, i have a 14'' aluminum pully, cut from solid aluminum plate , then a channel is milled around it for the belt to ride in . the channel iv milled flat instead of a V so i can turn a v belt backwards an it will free spin and not grab till i put tension on it. the connecting rod is mounted off center and it works off concentrics. as of now my smithy isn't up and running 100% but soon as it is first thing i gotta do is replace my springs, busted a leaf earllier in the year. i just use old truck springs, i use three of them but think when i replace them im gonna use for to see if it hits any better.
 
Hey I love it. How much horse power does it take to run this thing. How big is the tire and the drive wheel.
 
Takach, I am going to use a fresh leaf pack or get some straight seperate leaves for the upper bit, same problems that happen with leaf spring knives I don't want to happen to my hammer, with the potential to kill me much more than a knife with a crack. I like the design of the tire hammer drive system better than all the seperate belt and pullies, much simpler, less moving parts.

AZMike you are right 100%, it has the drive design off of a tire hammer with the mechanics of a rusty type hammer, top is a truck spring.

IB, shouldn't take more than 1HP, the tire is a spare tire and the drive wheel is 3 or 4 inches.
 
Hi Sam,

Seems like a cool design. Definitely a cool CAD rendering. I just recently started trying to develop a basic understanding about power hammers. Wonder if you'd be willing to field a few remedial questions?

  1. What kind of relationship does the hammer stroke distance have to the tire center and its off-set drive shaft? In other words, if you have a ten inch hammer stroke is the distance between high and low on the tire drive also 10" or are there other factors to consider, such as the helve lever action?
  2. How much space are you allowing for total tooling gap of the various hammer and anvil tools and dies? Do you add this total tool/die height to the stroke distance to get an overall maximum gap measurement from anvil "floor" to hammer "floor"?
  3. What will be your anvil height, average anvil tool height and resulting average working anvil height? How is the height arrived at? I picture smiths holding hot iron out in front of them about bellybutton height with their elbows braced against their sides/hips, but am not sure if that is a sound working stance (having never done or seen it), thus I'm not sure if that would be a sound premise to base one's anvil height on. I also don't know how working the treadle would factor into this.
  4. Is it possible to roughly calculate expected BPM? For instance, is there some equation one could project from (given there will be friction loss) based on motor RMP, drive wheel diameter and tire diameter?
  5. How does the actual operator control mechanism work? Is the whole motor actually mounted on some sort of pivot and you're using your treadle to lift its hind-end up thus pushing its front-drive-wheel-end down against the tire? Can you describe the pivot mechanism, motor mount, treadle linkage? Is there some sort of resting idle position and how is that achieved? Correspondingly, would a maximum lift stop need to be built in too, or is it not possible for the treadle operator to exert too much pressure?
  6. How much leg strength do you expect you'll need to exert on the treadle for full force hammer power? What are some typical hammer duration periods for basic "full bore" drawing out?
  7. How refined will your control be? How gentle a blow can you administer? A single one? Do you expect you'll come to be able to stop the hammer in any position you want?
  8. I didn't understand the hammer lift spring you described. Sorry, can you give that explanation another go?
Well that's it for now I guess. Hope this isn't too presumptuous of me. I've enjoyed all your posts and thought I'd see how far your willing to stretch you're sharing...

Thanks, Phil
 
Hey guys,A friend and I built the first two tirehammers from a sketch by buddy Ray Clontz.These hammers are about 6 yrs. old and still going strong.My hammer dosen't look like much,but it has made me a good many $.Mine is powered by a 1/3 hp motor,A very simple design anybody with fab skills could build,it uses a little giant type linkage,which is where you get your bang.I would be glad to help anyone who wants to build one.Clay Spencer is doing workshops to build these hammers,over 200 built,he changed the slide design to use a tup in a tube.

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Hey Butch I'd love your assistance. I've emailed Clay a couple of times to order his plans, but I've not heard back from him. At this point I'm basically in scavenger mode and need to know what to look for in the way of metal and parts.

I believe I have a suitable piece of steel for the "backbone". I just found a small rim and tire today, but the tire's steel belt is shredding through, thus would need to be replaced.
  1. What kind of stuff might I find in a scrap yard that would make a good anvil?
  2. How heavy of a base is required?
  3. What's needed for all that spring linkage etc.?
  4. What kind of metal do you use for the ram?
Looking forward to learning more. It was great following Sam's treadle hammer project. This looks to be even better.

Thanks, Phil
 
Sam,

I think that you might have an issue with the orientation of your flywheel/eccentric. I think that it might cause two problems: rocking of the hammer side to side, and also applying a twisting action on the leaf spring. Both of these would be eliminated if the flywheel/spring were on the same plane and not perpendicular to each other. Nice modeling by the way.Which program do you use?
 
Thanks Stevo, Maybe with the wheel mounted down so low and the hammer bolted to the concrete/wood base there won't be a problem with rocking. You bring up a good point though about the twisting action, I oriented the tire to be flat to the back liek that to minimise the space taken up, and looking at it again it would require MUCH less parts to just flip the tire to the side to be inline with the spring, but could work either way by just turning the pivot at the top 90 degrees. if it came down to a bit more work to make it so the tire was not stuck out the back I would atleast give it a try, i'll have to see when it comes time for the build.

Edited design:

l_5978c9b74e0ea43c45d07f9d5de723cc.jpg


And thanks, I used regular old Paint program, sure wish I had and knew how to use CAD and stuff, or one of those cool ones with the animation simulations.

Farmer Phyl said:
and thought I'd see how far your willing to stretch you're sharing...
Click to expand...

While I don't in any way enjoy being "tested", I will do my best to answer your questions when I have a chance.
 
Sam Salvati said:
While I don't in any way enjoy being "tested", I will do my best to answer your questions when I have a chance.
Click to expand...

Thanks Sam. I guess what I said came out sounding weird. No character evaluation intended...I'm not qualified. Anyway, you're obviously way above par! I really have enjoyed all your posts, THANKS!!!!
 
I really like it Sam. I don't see that much of a problem if you have a good pivot at the top. Very doable to and at fairly decent cost. I am going for a hydraulic press first myself. But. dam this looks good. Please keep us informed as to dimentions and problems etc as you move along. Jim
 
Sam,
An engineering observation on the helve - Make the pivot bearing movable up and down the top of the frame (maybe 12" overall travel) to fine tune the period and harmonic of the helve arm. Slide it slowly forward from all the way toward the drive shaft ( tightening the bolts down each adjustment) about 1" at a time. At some spot it will suddenly start beating smoothly and you will feel the vibrations quiet down.
The 90 degree opposition of the drive wheel to the helve may cause some problems,as Steve pointed out.

I have plans for a "Rusty" somewhere. I was going to build a small movable unit, but never did.....yet.When I move to the country and built the uber-shop, I'll probably build all sorts of equipment I won't need.

Farmer Phyl,
The post on a power hammer can be anything that has mass and density. At a scrap yard, look for a piece of round or square stock that is about 24-30 inches long and 6-8 inches round/square. That would make it somewhere between 300 and 500 pounds. Type of steel won't matter.The dies will be what you want a good steel for.
Stacy
 
Thanks IB, i'll be sure to take a bunch of pictures and detailed specs when it comes time for the build.


Stacy, do you mean the top pillow block or the pivot the red arrow is pointing to(in the last picture)? Once I get this one built, and have some power hammer know how under my belt, I will build the ones I have had plans drawn up for that is portable and gas powered, that can be bought almost entirely and just assembled very cheaply.
 
The main pillow block.
This is the fulcrum of the helve, and also sets the period of the arm's harmonic. Just a little bit one way or the other will make a lot of difference in how the ram strikes, and the amount of vibration. Improperly tuned, it can rip bolts loose, and even cause the helve to break due to fatigue.
Stacy
 
OH ok, I didn't know the pivot point was so critical, thanks. I will drill a series of holes in the top for that adjustment. i thought the critical adjustment was the length of the connecting turnbuckle, and the position of where it connected with the top helve.
 
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