Heavy hammers

[Isaac sur Noos]

Richard hello,

I will ask you to explain, how your beloved Pythagoras would deal with
that :

10 mm key dip give us, to simplify 50 mm of hammer rise.
So the multiplication is simple enough : 5 for 1

Then, according to the law of levers ...

10 g hammer weight presumably will need us 50 g DW to be balanced (and
not BW , which is a very different notion)
12 g hammer weight then will give us 60 DW.

Thanks for proving your point, or explaining what you are trying to
say.

Isaac - while indeed the actual possibility that a hammer are 2 grams
too heavy is a little extreme, anyway to have even 1.6 gms off a
medium hammer is not a such simple task in my experience, particularly
if one does not want to file some felt around,
the best gain in weight comes from the sides thinning IMO, not
practical when on the shank, shaping the felt shoulders on a drum
sander may be fast enough, but difficult to do accurately, a good
final shaping will be due nowadays.

Original Yamaha heads being sold undrilled, I see no easy solution if
the problem comes from the heads.


Regards and thanks for clarifying .

Isaac OLEG







> -----Message d'origine-----
> De : pianotech-bounces@ptg.org
> [mailto:pianotech-bounces@ptg.org]De la
> part de Richard Brekne
> Envoye : vendredi 9 janvier 2004 13:05
> A : Pianotech
> Objet : Re: Heavy hammers
>
>
> Folks.. not meaning to be picky here... but just to be on
> the safe side,
> perhaps its a good idea for the sake of clarity to
> underline that we are
> talking BW here, and not DW.
>
> A couple posts have come by equally vague and to the unitiated its
> really easy to relate this to Downweight.
>
> 1 gram change in hammerweight yields about 5 grams change in BW.
>
> Specifically : change in SW * SWR = change in BW
>
> > General rule of thumb is that for
> > every gram of weight you remove from the hammer you
> remove 4-5 grams at the
> > key...mileage varies but that is close....
>
> > 1 gram on the hammer is approx 5 grams on the touch.
>
>
> That this can get confusing is easy to see in one post advised
>
> > "But if you really have to go back from 65 g to 52 you
> have to obtain 2
> > gr less on your hammers more or less"
>
> Clearly the postee was thinking in terms of 1 gram of
> hammer weight to 5
> grams of DW, and this is wrong. If the questoner had
> removed 2 grams of
> hammer weight the resulting action would be extremely light.
>
> Assuming that the above gram figures are Downweight figures, and
> assuming any reasonable UW you get an increase in BW of 6.5
> grams. Which
> relates to about 1.2 grams of hammer SW.
>
> Cheers
> RicB
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