My power hammer :p

Well, not really. Lately I have been focusing on laminating steel and making things that look more interesting than monosteel. One of the side effects is the need to draw out thick billets. The first couple of times I did this with a hand hammer, which takes ages and causes lots of scale loss.

Last time I had a friend come over to be a striker. It was a lot of good fun and we made him a laminated knife. The problem is of course that this is not something I can do whenever it suits me, and while he means well, he doesn't hammer quite as hard, fast, or precise as I would want. That is logical of course. So I kept thinking about a better (faster) way to turn a thick billet into usable stock.

I spent the entire Friday afternoon tinkering in my shop, trying out several things, scrapping and rebuilding it as I went along. I welded, cut, and welded again. The result is butt ugly, but after today I know it works really well.

Basically, it is a hardy tool that is slotted for a 30 mm wide bar of stock (which I use as a center steel for my billets for now) and which uses threaded rod to clamp the bar to the bottom plate of the hardy tool. The fit is exact, so when the bar is in there, there is literally no wiggle room. First I do the initial hand welds with a hand hammer to make sure that everything sticks together. The I repeatedly bring the billet to welding heat, clamp it in, and beat the billet with a sledge hammer. As soon as the color drops below yellow, I release the clamp and reheat. This worked very well. Initial heating and welds aside, I drew out a 1" thick billet to less than 3/8 in half an hour. The additional benefit is that the bigger surface of the sledgehammer means that the surface will be pretty flat instead of dished.

I'll have to make a couple more of these things. At least one or two for when I use 25 mm stock or 20 mm stock. And then another for when I work with square 10 mm bar which was welded to a billet.

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I think that is quite ingenious, Bruno!
(I also feel much better about my welding! :rofl2:)

Bruno, it's not the looks , it's that you got to where you wanted to be by building something that works. Can't tell you how many butt ugly tools I have made. Try and buy a 6" wrench or a vice that holds a 300 pound hydraulic ram.
Good going :<0)

That is one sturdy looking hold down fixture, Mr. Bruno!!!! Nice work.

One of the side effects of laminating steel, is that afterwards, the effects of the hammering is visible in the layer patterns. With only 5 layers, this is pretty distinct. And this tells me a lot about the flaws in my techniques, flaws that will never be obvious with monosteel, except during heat treatment perhaps.

The more you work, the more you get experience. Sometimes the result is pleasing, and sometimes not. But the road by walking.

As best as I can tell, a small rolling mill like a McDonald design is about the only "home shop" way to get layers that are close to "straight". Some folks do say that a press will not distort "enough" but those guys have nice big presses that take big bites, I suspect. My small one distorts the pattern pretty nicely.

If you could come up with some type of a quick clamp & release Clamp"Does that make sense??" It would give you more time at welding heat. I have seen some foot operated clamping devices. Just a thought.

Slawman

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Originally Posted by Slawman

If you could come up with some type of a quick clamp & release Clamp"Does that make sense??" It would give you more time at welding heat. I have seen some foot operated clamping devices. Just a thought.

Slawman

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I've considered that. I've tried a couple of variations as well.
The thing is that as long as the steel does not touch the anvil solidly, it doesn't lose heat quickly enough to be a problem.
And quickrelease mechanisms often have a problem with snapping open or allowing wiggle room when the billet is under heavy impact.

If you don't open the clamp more than is needed, then closing it is pretty quick as well.

Nice idea, I can think of several uses for that on my anvil and I will be copying your design.

I don't do laminated steel yet, but for a quick set and release clamp that will hold up to the banging, take a look at a carpentry hold fast.

I did. They then to jump open during the impact on the thing you are hitting full on with a sledgehammer.
I'm sure that can be solved somehow, but hold-downs are not really means for impact use

Sounds like the hole for the holdfast was a bit too large.
I use a 1/2" diameter hold fast in 9/16" hole. The hole is 3" deep through a steel bar. The steel bar is welded to a square tube on the bottom so that when I put the bar and pipe into the hardy hole it will sit flush with the anvil face. I've hit things with a 12 pound sledge and the holdfast didn't come loose until I knocked it loose.

Or maybe the smithy gods were smiling on me when I made it. :)

Yeah maybe I was just using the wrong kind or something.

I use the Roubo style holdfast of hand forged iron. The cast iron ones aren't "springy" enough to hold and often break.
It takes about 30 minutes to beat one out.