Backchecks height - tails length

[Isaac OLEG]

Without knowing for sure I may say that if the tails are shorter, that
looks like a sign of a good adaptation of the bore to an uneven
string's height, that occurs (was said) when the plate warps too much
when getting cold. Differences of a few mm in the medium ranges are
seen on some pianos, boring to keep the same attack angle of the
hammers shorten the tails.

I've seen some where the bore followed the string's height, and others
where it was "standard" while the string's height was not, causing
over centering, and the tech screwing the regulating balance rail
screws more than usual.

Over centering hammers are not well known for the strength of tone
they give, and this is not IMHO , only a question of letoff.

???

Isaac



Isaac OLEG

Entretien et reparation de pianos.

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> -----Message d'origine-----
> De : pianotech-bounces@ptg.org
> [mailto:pianotech-bounces@ptg.org]De la
> part de Richard Brekne
> Envoye : mercredi 28 mai 2003 18:48
> A : davidlovepianos@earthlink.net; Pianotech
> Objet : Re: Backcheck height
>
>
>
>
> David Love wrote:
>
> > Why do you have to replace the backchecks in order to
> lower them?  Just tap
> > them down.
>
> Well... grin... course you gots to make sure the wires
> arent already buried as
> deep in the key and backcheck as possible already... but
> otherwise... correcto
> !!... tap them, press them, or screw'em in there a bit
> deeper as it were.
>
>
> > The backcheck being to  high won't in and of itself create
> > problems with low checking.  But the fact that you must
> move the backcheck
> > away from the hammer to keep it from dragging on the tail
> on the way up or
> > to keep it from hitting the low shoulder will.
> Suggestions by Ed Foote
> > were right on the money.  The radius of the tail must be
> 1/2 the hanging
> > distance (1/2 x 5 1/8" = 2 9/16"), the low shoulder on
> the bulkier hammers
> > may need to be trimmed away if they are too low, and the
> backcheck height
> > will have to be set along with the angle of the check.
> The angle should be
> > such that you can push the hammer into the check, but
> you should get
> > increasing resistance as you go down.  If the angle is
> too acute and you
> > cannot push down at all, you will get what's known as
> "hard checking" and
> > you will feel it through the key.  If the angle is not
> acute enough, the
> > hammer will push through the check and with hard blows
> you will get
> > checking that is too deep.  The other problem that occurs
> on Steinway
> > hammers is that the tails can be too short.  Check the
> length from center
> > of the bore.  It should be 1".  Often it is not in the
> tenor section.  That
> > will also make high checking a problem.
>
> I asked the Steinway tech in town for the Festspill about
> this, and his answer
> of course was very much in defence of Steinways view on the
> matter.... which was
> more or less... "If Steinway made the tails a bit less then
> 1 inch long on any
> given piano, then you can bet your bootie that there was a
> good reason for it".
> I just love these highly informative type answers you get
> sometimes :)
>
>
> >
> >
> > David Love
> > davidlovepianos@earthlink.net
> >
>
> Btw Avery... thanks for posting those two proceedures
> recently. Been reaallly
> buzy with two festivals going on in town, so my replies are
> abit delayed.
>
> Cheers
>
> RicB
>
> --
> Richard Brekne
> RPT, N.P.T.F.
> UiB, Bergen, Norway
> mailto:rbrekne@broadpark.no
> http://home.broadpark.no/~rbrekne/ricmain.html
> http://www.hf.uib.no/grieg/personer/cv_RB.html
>
>
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