hammer "throw" on hard blow

[David Nereson]

David Nereson wrote:

>    I often encounter, when using test blows, hammers that get "thrown"
> left or right on a hard blow, missing one of the strings of the unison,
> even though they hit all three on a soft blow.  This can happen just as
> often on straight-bored hammers as angle-bored ones.   I'm not sure
> why.  You can move the whole flange/butt assembly left or right so all
> three strings will be hit on the hard blow, but then on a soft blow, it
> barely contacts one of the outside strings.  Does the flange twist or is
> the jack pushing one side of the butt (or knuckle) harder than the other
> or what?
>    A similar situation is that of the "rubber shank."  But usually
> "rubber shanks" wobble badly during and after the blow, like throwing a
> knife into a tree, where after it hits, the handle wobbles laterally
> (doing-oing-oing-oing-oing-oing...).  This hammer being "thrown,"
> however, is mainly during the blow, and no wobble after impact with the
> string.
>    How to correct?
>    --David Nereson, RPT


Oh, and I forgot to mention-- I already checked the obvious:  the flange 
screw is tight, the flange does not need re-pinning, and all glue joints 
are sound. --D.N.

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