Summary

After toying with a model of doric column I really wanted a column with proper entasis. I think there may be a minor error in my math... If anyone has a better solution I'd be very interested to see it.

edit: I figured out what was messed up in my math, but have no reasonable solution yet... doh!

edit 2: I think I figured it out.

Instructions

So the scad for this is semi-parameterized; the arc_r variable is the radius of the arc of the entasis of the column. Using the values in the file will result in 5/6 entasis on a column with a base width of 12 and base/height ratio of 1:5.5 AFAICT these dimensions are period correct for a greek doric column, but I haven't accounted at all for the capital of abacus. The bottom 1/3 of the column has straight sides, however I've seen some diagrams that indicate that some columns may have the entasis arc continued smoothly through the bottom 1/3 as well.

At any rate this is probably a decent start for anyone wanting to do greek architecture without having to figure out all the math. The wikipedia article on trigonometry and solving triangles was very helpful :)

An attempt at a greek fluted column