Is this a conical section, or an annoying elipse?

This is some cardboard mockups I created before cutting the deck rails for the Fire Boat.
I basically cut the rough shape, and then add 1/4"-1/8"- or 1/16th of an inch to top or bottoms till I get what I want. Usually takes two or three tries.

If it is a simple conical section, and you know the small and large diameter and the hieght of the cone, then you can use the "Shroud Calc"

http://www.realmcommunications.com/r...shroudcalc.htm

[8D]