Hi,

I have a 30 ft round 16'' log. I have cut it to 40 degree (10:12 roof pitch) and a flat surface on top.
This will become the purlin beam on my post and beam system (using round beams and square posts).

The problem is that I do not know where the centerline is on the purlin. How can I find/choose the centerline of the beam with everything already cut? The log is a typical rough round log that has different diameters throughout (ie. not perfectly round).