Appalachian power hammer questions

J

Jason Fry

Knifemaker / Craftsman / Service Provider
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Jun 5, 2008
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I'm working on a power hammer in my head. I'm planning a Rusty style helve hammer. Final size to be determined by how big of an anvil I end up with, and how big of set of springs I can scrounge.

I'm going to use a tire clutch rather than belts and pulleys. I'm still stuck on whether to use the tire hub as the flywheel/eccentric, like on a tire hammer, vs. using the tire as the clutch only and having a separate flywheel/eccentric on the other end of the shaft.

Anybody have any ideas on which would be better? I'd love to see pictures of that part of your hammer, if you've got one.
 
I'm slowly collecting materials for a rusty. My plan was to have an separate eccentric/flywheel. When the rubber wears out, then I can unbolt the rim and change like a normal tire, which I think will be easier than trying to work around the flywheel if it's built right into the rim. The big question for me is how long does the rubber last? If it lasts long enough, it may not be worth the trouble.
 
A separate flywheel adds more mass, and takes care of some other problems like vibration. Two pillow blocks for bearings and a shaft between the two wheels deals with mounting. With some fairly simple welding and such you can use the hubs to mount the wheel and flywheel to. You can also keep the tire on the flywheel to add more inertia and mass.
 
A long time ago I built a Appalachian hammer. I was not impressed. It worked, but I really didn't care for the slack belt drive, and it didn't hit that hard. It did work lots better than a short handled sledge I had been using. I much prefer the toggle link Clay Spencer tire hammer though. One thing about the Dupont style linkage is that the faster it moves, the harder it hits. Also was pretty underwhelmed with the so called "instructions" for rusty and dusty. Give me exact measurements and then make suggestions on substitutions and changes, don't send plans with "about here" and "about this big".

From what I've seen, most rocking beam hammers are on the heavy side to make up for the added power that a toggle link system has. A toggle link, or similar linkage, "slings" the head down to cause a harder hit. If I was to build another rocking beam hammer I'd want the head to be around a 100 to 150 pounder.

One advantage to the rocking beam hammer is that if you build it rite it seems like it'd be better for blacksmithing and tooling as it can run slower and hits straight up and down. The toggle link tire hammer seems to be better for drawing out and isn't as accurate as a rocking beam as it's got a little concentric wobble to the head. Either can be used for either use, but for turning large stock high carbon into smaller stock I really prefer the toggle link tire hammer. For setting up tooling plates and such I'd love to have a rocking beam hammer. That said, there is not a huge difference between them if done rite, and either will be loads better than a sledge hammer and a worn out arm. You can build tooling for either as well.

If you do go for the rocking beam hammer, using a tire as the clutch is a definite improvement over the slack belt drive.

I'm dreaming of an air hammer right now, but I also keep looking at Anvilfire's X1 110 pound hammer. Partially as it'd be really useful, partially as it'd be fun to build.
 
One other hammer style that is better than swinging a sledge is a treadle hammer. It is usually run by your foot, but I saw one that was converted to run off a pneumatic cylinder and was "triggered" by a simple foot switch. It obviously wasn't near as fast in striking as a power hammer, but was roughly the same speed as a treadle hammer without having to use leg power to make the blow. IIRC, it ran off a big shop compressor.
 
Good point, I've got an inline treadle hammer I built and while it won't move metal near as fast as a power hammer or press, I'm really surprised at how useful it is. And with drawing dies it will move a lot more metal faster than one sledge hammer. Only downside is it's rough on my creaky knees, so the air conversion would be something to think about.
 
I have a treadle hammer already, that I've added rounding and flatting combo dies to. It's better than a hand hammer, but like Will said, it'll make you want a power hammer pretty fast.
 
OK, so I went to my friend's epic scrap pile and he has 98% of everything I'll need for an Appalachian style hammer. I may shoot for build-along pics as I go, but for now I have some specific questions about materials selection. He's got so much to choose from!

First question... Let's say I have the choice between a dozen different sizes of leaf springs. Shooting for a 300 pound anvil and 25-30 pound head.

Should I look for a shorter set, 36-40" or so, to minimize the footprint? Or, would a longer set, 60" or so, have better performance?

Next, should I look for a heavier set, so they functioned more like a solid bar, or for a softer set, so that I get more whip?

What would your ideal set be?

Next, questions about the anvil, and the head size and material.

He has some kind of solid axle, 4.5" round, by 60" or so long. Math says that a 36" piece weighs 162 pounds. This by itself isn't enough for a 25 pound head, correct?

Next, he has a mud pump sleeve, easily 150 pounds, about 20" long with a 5 or 5.5" bore down the middle. We're thinking we could use some pipe to shim the gap, weld it all together, and get close to 300 pounds. The solid axle would go straight from the dies to the base plate, with the sleeve on the bottom for extra mass.

Is this a good idea? The 4.5" solid round is the biggest solid we could find.

He also has 2" or 2.5" (eyeballed) square solid stock. 18" of 2" is 20 pounds. 12" of 2.5" is 20 pounds. Along with that would be the roller assembly, the die plate, and the dies, to calculate the head weight, correct?
 
Go with the 2.5" head.
The built up post should be fine if fully welded up on both ends.
The heavier the base plate the better, so look for the thickest piece he has, and consider adding a double layer of plate under the post.

Choosing the springs is going to be trial and error, but stiffer is probably better than lighter.
 
J Jason Fry here is a shot of the tire clutch area on the power hammer I just finished.
6jVbF38m.jpg

And a shot of the whole thing I need add some more weight to my anvil it's only about 300 lbs and the ram is about 48 lbs . I added a counter balance to the eccentric and that really helped with the rocking.
shNGLLcm.jpg

Another shot one heat on a jackhammer bit I made into a hot cutter. My shoulder is very happy.
83xmyQJm.jpg
gQXKTLjm.jpg
 
Thanks, Gilbert. That tire/eccentric shot is great... nobody shoots that part in a way you can see it. That's pretty much exactly what I had in mind.
 
Hey Jason, any progress on your hammer? I’m thinking of pondering the possibility of maybe making one some day. Perhaps.
 
Funny you'd ask just now... I spent all day yesterday on the initial design and parts cutting. I'll start a separate build along thread.
 
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