Down bearing

[Isaac OLEG SIMANOT]

Terry,

I am talking of 3 feet gauges of different lengths. Easily made with stock
wood and screws or any regulationable part with a flat base .
The longer length gives a very precise measure, i.e. if length is twice the
back string length and you want a 3 mm computed DB, you will have to obtain
twice as that on the other side (you will need a few strings mounted of
course).
Beside, it is easier to measure on the bass strings because you can regulate
the height of the foot of the gauge to take in account the size of the
string.
For a "in the ball park" mesure while installing frame and basic setup, the
thread method is well enough, but I hardly can fine tune the DB with that
method, particularly if it is minimal.

The Lowell on Bubble gauge, is nice to understand the bridge geometry, but
it can gives you a lecture of no Down bearing if the slant of the bridge is
a tad pronounced and if the board have sunk a lot, then, the back length
gives a negative lecture and you can't see no down bearing.
The easiest method on a strung piano is to take a hammer/string distance
gauge, as the yellow Yamaha one, but with a longer handle. You put the gauge
along the string in front of the bridge. If any gap exist on the other side
you have apparent down bearing.

HTH

Good joking day (is there any particular name for April 1st ?)

Isaac OLEG



> -----Message d'origine-----
> De : owner-pianotech@ptg.org [mailto:owner-pianotech@ptg.org]De la part
> de Farrell
> Envoyé : dimanche 31 mars 2002 15:13
> À : pianotech@ptg.org
> Objet : Re: Re: Down bearing
>
>
> "It is way more precise to have some home made gauges of
> different lengths,
> that can help you to ascertain the existing bridge and strings segment
> geometry."
>
> I use a bubble guage. Could you please expand on your suggestion
> of precise home made gauges of different lengths? Thanks.
>
> Terry Farrell
>
> ----- Original Message -----
> From: "Isaac OLEG SIMANOT" <oleg-i@wanadoo.fr>
> To: <pianotech@ptg.org>
> Sent: Sunday, March 31, 2002 4:53 AM
> Subject: RE: Re: Down bearing
>
>
> David,
>
> When apparent downbearing is small it is very easy to be fooled by these
> commercial 3 feet gauges sold......
>
> SNIP
>
> It is way more precise to have some home made gauges of different lengths,
> that can help you to ascertain the existing bridge and strings segment
> geometry.
>
> SNIP
>
> Regards
>
> Isaac OLEG
>
> Francium
>
>
>