POWER HAMMER THEORY The fact is that MOST of a power hammer is anvil. It is an inescapable law of physics. Many try to reduce the anvil mass for economic reasons but economics do not take precidence over the laws of physics. Take the mass out of a power hammer anvil and the force HAS to go somewhere else. Moving the work instead of shaping it, into the floor of the shop OR bending stretching and braking the machine. |
THE General rule for the ratio between power hammer anvil and ram has been 15:1 and for heavy duty use 20:1.
The Little Giants to the right meet that ratio without including the frame. That's right.
The cheap little 'farmers' hammer meets the 15:1 rule! We calculated that for all models from 25# to 250#
Compare that to the "average" anvil in a "general" shop, 200#. The average hammer used on that anvil is 4#. That's a 50:1 ratio! Perhaps the smith has a team of strikers with 12# sledges. That's still almost a 17:1 ratio. OK, so YOU have a little 100# anvil. You probably use a 3# hammer or smaller. That's still 33:1. SO, What's the difference? Velocity, you swing the hammer faster and hit harder for a given hammer mass than the power hammer. Remember that when you compare how much metal a power hammer moves compared to you per blow. |
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NOT a believer yet?
Lets look at power hammer anvils from a different view.
All anvils are a mass in space.
So lets imagine the anvil is floating in outer space. First case, strike the anvil with a hammer of equal mass having an arbitrary velocity of 10. The anvil at rest now moves away from the hammer at a velocity of 9.99 (there is always some loss) and floats away into infinity. Hmmm. . not a very good anvil. But this is what physics tells use will happen Second case, strike the anvil with a hammer of 1/10th the mass having an arbitrary velocity of 10. The anvil at rest now moves away from the hammer at a velocity of .990 (there is always some loss) and floats away into infinity. |