I'm trying to put a _very_ subtle curve on the bottom of some table
aprons. I've placed some nails in the apron templates at the
appropriate points and used a piece of 1/8th" thick wood to try to
draw a fair curve but, (whether I drink to much coffee or I'm just not
good at drawing), I'm not liking the resulting lines, so I'm hoping
I'll get more perfect results by using a (_very_) long trammel arm on
my router to do this.


The height of each arc will be 1/4" above the baseline of each apron.
The center point of the long aprons is 25-3/8ths from each end, and
for the short aprons the center is 9". Like I said, these are going
to be very subtle curves, but visually important and I want them
perfect. ;


How would I compute the radii of the circles I would need to give me
the arcs for each apron?

(Alternatively, is there another method that doesn't rely on how
steady my drawing hand is in order to do this?)

Michael "Shakey" Baglio