You may recall that I queried the group about an equation to find the radius of a circle in order to draw an arc for a bit of molding for the buffet I'm building with my son. We elected to drive a couple of screws at the end points, clamping to those a thin strip arched to the center point. I held it at the center point and he drew the arc. A few minutes at the bandsaw and a few more minutes at the oscillating sander -- okay 20 minutes at the sander -- and voila.

We're in the home stretch. On to final sanding and finishing. Pix to come..

Larry

Gramp's shop wrote:
You may recall that I queried the group about an equation to find the radius of a circle in order to draw an arc for a bit of molding for the buffet I'm building with my son. We elected to drive a couple of screws at the end points, clamping to those a thin strip arched to the center point. I held it at the center point and he drew the arc. A few minutes at the bandsaw and a few more minutes at the oscillating sander -- okay 20 minutes at the sander -- and voila.

We're in the home stretch. On to final sanding and finishing. Pix to come.

Larry

You did it the intuitive way. Good for you.

When I built my Japanese bridge, I knew the width and height at the
center. I made a compass out of a long strip of wood anchored by a
nail into a piece of two by. By trial and error I figured out the
radius (around 14-16 ft), drilled a hole in the strip to hold a pencil
and drew the lines on the pieces of treated 2 x 12 and 2 x8 to make
the sections.

Cutting an arc on a long piece of 2 x 12 with a bandsaw is a lot of
fun when you have no helper.

--
 GW Ross 

 In nature, there are no rewards or 
 punishments, only consequences. 

On Sunday, April 28, 2013 8:37:06 AM UTC-5, G. Ross wrote:
You did it the intuitive way. Good for you.

And the more you do, the easier it gets, especially with smaller arcs or curves. You develope a knack to freehand them. It pays to have round eyeballs, though, to make perfect arcs/curves. Better still, when it comes to those tricky double "S" curves, it pays to have one eyeball rounded one way, and the other eyeball rounded the other way.

Sonny

On 4/28/2013 8:09 AM, Gramp's shop wrote:
You may recall that I queried the group about an equation to find the radius of a circle in order to draw an arc for a bit of molding for the buffet I'm building with my son. We elected to drive a couple of screws at the end points, clamping to those a thin strip arched to the center point. I held it at the center point and he drew the arc. A few minutes at the bandsaw and a few more minutes at the oscillating sander -- okay 20 minutes at the sander -- and voila.

We're in the home stretch. On to final sanding and finishing. Pix to come.

Larry

In fact that is the idea behind the mathematics of spline functions. It
grows from the way that New England boat builders ages ago used thin
strips of wood (called splines) to make a smooth curve through certain
required points, where the hull's side boards had to meet bulkheads I
will guess.
Bob Wilson