[TheForge] Re: uri hammer

[xlch58 at swbell.net]

Sorry, missed the web page url?   What was it?

Charles


Mike Spencer wrote:

>>Hmm.  Looking at the web page, I wonder if you ever figured
>>out the energy imparted to the hot iron by the hammer head?
>>    
>>
>
>Well, I have a little trouble with the computations. [1]  But as a
>first approximation, the kinetic energy of the hammer head is:
>
>    1/2 X mass-of-hammer X velocity-of-hammer X velocity-of-hammer
>
>    1/2 m v^2
>
>If the hammer head stops dead with no rebound, then there's zero
>kinetic energy so all the kinetic energy of the hammer must have been
>converted into work in deforming the the iron and is eventually
>dissipated internally as heat.  If there's rebound, that kinetic energy
>has to be subtracted from the original KE to get how much went into
>the iron.
>
>Rebound is hard to measure with a hand hammer.  And the above ignores
>all the other possible variables such as energy absorbed by the anvil
>and stump/stand, energy dissipated as sound, etc.
>
>Those pics on the web page were done with hot iron.  We did some
>others with a piece of lead and with a piece of cold steel at faster
>frame rate.  I haven't gone over those carefully but intuitively,
>there was less rebound with the lead and, of course, a great deal with
>cold iron.
>
>Thinking about this stuff is for the winter when the shop is cold, the
>snow deep and the house warm.  Maybe this winter.  I finally found
>some manuals for Maple V and mean to play with it when the weather is
>nasty.
>
>
>- Mike
>  
>