Hey y'all,

I was looking at some photos of power hammers on google images and found this style power hammer head assembly.

What is this style head assembly called? It looks fairly simple to build. Would it work as a substitute for a tire hammer style assembly?

Thanks y'all
Trip

use the bow spring setup there with your tire drive/clutch.

That particular hammer is, I believe, a sheet metal hammer.
Which doesn't tell you much, but the configuration is commonly found on Japanese mechanical hammers, and older US and European hammers.

Sheet metal hammer, looks almost like a Yoder or a clone. Very small stroke, made for sheetmetal. Closest similar design is a Japanese knifemakers hammer.

Sheet metal hammer, looks almost like a Yoder or a clone. Very small stroke, made for sheetmetal. Closest similar design is a Japanese knifemakers hammer.

What he said!



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The bow spring linkage was common on lots of old mechanicals, including but not limited to the Justice Hammer, Champion, Williams and White, Scrantons, and a large number of others. You could certainly put a bow spring linkage onto a tire hammer crank instead of a Dupont linkage on a tire hammer crank, but you will need to custom make your springs. With the current tire hammer designs you buy a stock spring and fabricate the arms. Both are viable, figuring out which is easier is up to you.

Well I have been doing some reading online about this type of assembly and it looks a lot simpler.

Could I not use a car leat spring? Looks like what they did here http://www.anvilfire.com/power/safrica/mech1.htm

Thanks y'all
Trip

Yes you could use an auto leaf spring, but please look closely at the online pics. The shape is not quite the same as an auto leaf spring, and the number of stacked springs and where each overlaps the spring below is probably different than what you can buy at the auto parts store. One of the things that a power hammer spring does is decelerate the ram on the up stroke. Think about what may happen if the curve of your spring is too shallow and the ram doesn't have room to travel inside the curve of the spring.

If you want to use off the shelf parts for a hammer look into the Rusty/Krusty design, originally called the Palmer design.

The hammer in the last two pictures is made by Renato Muskovic. It is a hybrid of a Yoder and Pettingel sheet metal hammer a real joy to use.

brad

opps

Note that I don't see any adjustment on the pitman so it doesn't have a wide range of different thicknesses you can work---not a problem when working sheetmetal as even 1/4" difference is a BIG difference in sheetmetal thickness---however in blacksmithing you may want to work 1" stock down to 1/4" and doing that by switching out how high the lower anvil is is not a lot of fun.

Building a hammer that doesn't work well for your needs is a rather expensive and time consuming folly.

There is a dovetail in the flywheel that allows the length of the stroke to be controlled. Beside the short stroke the hammer head only weights about 8-10lbs.

brad

Yeah... Dont be confused... Renato is a heck of a blacksmith (and a great guy) but this is not a blacksmith tool. These hammers have a very short stroke and a very high cycle rate ( that one is pretty big and I would guess is 1200-1500 blows per minute, the smaller hammers can hit up to 4500 times a minute) The heads are light, 15-20 pounds and the spring has very little "spring" actions, not like a blacksmith hammer. The spring is stiff and the leather belt is where most of the whip action takes place. The spring is there to keep the thing from destroying itself...

If you want to build a blacksmith tool look for something else to look at, this will just send you down the wrong path...

I should also say that this is a much more expensive tool than a blacksmith hammer... Last I heard Renato got around 20 grand for one of these....

Sorry ... I was not implying that these hammers were at all suitable for blacksmithing. But they are fun to play with.

That design is simply a smaller version of a Champion power hammer, with some minor differences. The design would work scaled up in size. If forging spring arms for that application i would use a known steel rather than scrap and have a professional heat treat done. Or do an extremely precise heat treat yourself with a temperature controlled forge. There is an entire thread here on Champion hammers

The spring arm is the same as a Champion, flywheel has zero application for a blacksmith power hammer as shown in the pictures you posted. You need a larger flywheel with a ratio similar to many common trip hammers

The spring shape is highly arched so that the tup does not hit the spring perch when the inertia carries it upward. This is also true for all "cross-bow" spring hammers.

Look into trailer parts as a source for the springs. There is a large selection of spring length and capacity. If I were going to build a bow stringhammer mechanism the spring is the last part that I would consider building up from scratch.

I suppose that you could anneal and reshape for the arch and then send them out for heat treating.