Rib dimensions

[Sarah Fox]

This is a multi-part message in MIME format.

---------------------- multipart/alternative attachment
Hi Ric,

You're right!  You came up with the same thing!  (duh)  8-P  Of course I =
did make it more user friendly.  ;-)  I think you have too much faith =
that people know how to use mathematical formulae without being given =
detailed instructions.

I also think...  that you enjoy mathematics far more than you let on!  I =
always enjoyed things mathematical -- very satisfying to solve a =
difficult problem.  My dissertation was very mathematical as well.  I do =
recognize others who have caught this bug!  ;-)

Peace,
Sarah

  ----- Original Message -----=20
  From: Richard Brekne=20
  To: Pianotech=20
  Sent: Thursday, December 11, 2003 1:50 PM
  Subject: Re: Rib dimensions


   =20
  Sarah Fox wrote:=20

    Hi Terry, OK, here's a more user-friendly method for you that will =
give you the correct position of the rib anywhere along its length.  =
(You can also use this method to plot out points on a template.  Compute =
numerous points and connect the dots.  :-) Clamp any part of the rib =
against a flat surface, concave side up (soundboard side down).  With =
this arrangement, let: h =3D the height of the rib above the flat =
surface r =3D radius of the rib d =3D the distance along the rib you are =
measuring, with respect to the clamp point.  For instance, if you clamp =
in at the middle of a 4 ft rib and measure at the end, d would be 2.  Of =
course this is approximate.  More accurately, d would be the distance =
from the clamp point to the position on the flat surface, directly =
underlying the measurement point.  (Think right triangles.) Then: h =3D =
r - Sqrt ( r^2 - d^2)=20
  Which is exactly what I wrote in my last post, exept I didnt specify =
that you could measure anywhere along the rib... figuring that was kind =
of self explanitory.. :)=20

  ""You could also do this simply by   r - Sqrt( r ^2 - (0.5L)^2)   L =
being the length of the rib. ""=20
   =20

  What I thought was neat about all the replies... is that we came out =
with two basic approaches... solving for crownheight, and solving for =
radius. So you can check either way you set up your rib jig. If you want =
a 60 foot radius.. then use the above... if you want to use a certain =
crownheight and want to be sure what radius you are imposing.. then use =
the formula Ron N put out.=20

  Cheers=20
  RicB=20
   =20

  --=20
  Richard Brekne=20
  RPT, N.P.T.F.=20
  UiB, Bergen, Norway=20
  mailto:rbrekne@broadpark.no=20
  http://home.broadpark.no/~rbrekne/ricmain.html=20
  http://www.hf.uib.no/grieg/personer/cv_RB.html=20
   =20

---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/e7/a2/db/41/attachment.htm

---------------------- multipart/alternative attachment--