Make a soundboard--Measurements

[David Love]

Actually, that was my question, what did you use to make the pattern for
the targeted radii?  My guess is that you didn't stretch a string out 25',
50', 60' etc. and scribe an arc, or did you?  My thought was to take a
piece of wood of a predetermined length and secure it at one end to a piece
of wood that will become the caul.   Draw a line along its length.  Then
calculate the amount of deflection off the straight line for an arc of
given length on a circle of x radius.  Then push the ends together until
you get that amount, of deflection.  Scribe a line.  Cut it out.  Question
is, will a strip of wood when treated that way form into a perfect arc? 
Any other suggestions would be helpful.

David Love
davidlovepianos@earthlink.net


> [Original Message]
> From: Ron Nossaman <RNossaman@cox.net>
> To: <davidlovepianos@earthlink.net>; Pianotech <pianotech@ptg.org>
> Date: 10/31/2003 2:30:22 PM
> Subject: Re: Make a soundboard--Measurements
>
>
> >What's the best way to make a shaped caul?
> >
> >David Love
>
> The first thing you try that works, as usual. I made up frames of 1X
pine, 
> cut to the appropriate radii, and covered them with a couple of layers of 
> plywood, totalling maybe 1/2".
>
> Ron N