"-MIKE-" wrote in message
...
On 4/15/13 4:32 PM, dadiOH wrote:
Gramp's shop wrote:
I need to draw an arc for a piece of trim.
The end points of the arc
are 5 feet apart and the depth of the arc at
the center point is 2
inches. What is the radius of the circle?

There ought to be an equation for this that
would be far superior to
trial and error, oui?

Trial and error isn't needed, neither is
knowing the radius of the arc's
circle.

Put two nails 5' apart in a piece of ply. Put
another nail 2" above the
line formed by the first two. Take a batten,
bend it between the nails and
draw the arc.


The potential flaws I see in that method are...
...you might get a peak/angle in the curve at
the center nail
...you can't always count on getting equal
bending at every point along the length of a
piece of wood.

I know it's a standard method to use a long,
flexible piece and
something to mark out a curve so I'm certain it
works. I would just want
to double check and practice a few times to make
sure the bendable thing
was bending equally.
-MIKE-


Perhaps the curve could be checked by flipping the
layout
stick end for end?