Alright guys, today i made a full length caul like the one Pearl Drums just posted and a took a few pics and measurements so here they are.
First i started with two 8 foot 2 by 10's, cut them both to 68" long and marked the center of one of them. then i started playing around with curves, using a metal yard stick to form the curves. when i found the shape i like i took a rough measurement, then removed the ruler to get a better measurement. luck for you i've recorded the measurements so you can just copy them if you wish. pretend the top center of the 2 by 10 is point 0,0 on and x, y scale, then just mark these points (inches) and drive a screw part way into the board.
X Y
0 -1
20.5 -2
26 -3
31.5 -5
33.5 -6
then use your metal ruler to form the curve and copy the line. repeat for the other side and head to the saw. I used a jig saw for the top cut since this is rather a large piece to handle on the bandsaw. i then marked second line below the curve and offset by 3" this i cut out on the bandsaw since i didn't care what this line looked like. line your curved board up on the backing board and screw it down, now bend some wood!
Thank you so much to Pearl Drums who posted his caul and got my kickstarted to build mine!