This animation shows the configuration of the two, mirror imaged, bastard valley bents. Each bent is comprised of a 35′ tapered (from 15″ down to 12″) octagonal bastard valley, one 21″ diameter “pacman” butt log post, two 12″ diameter interior posts (both with flats cut on them 7 degrees off of the centerline plane. These flats define the stairway corridor and flush out with the floor beams below), a small intermediate post, a tapered knee brace (10,000 lbs of compression at the log end!), and a horizontal tie beam. The Old Glory main peak log post is not shown as the bastard valley actually sits on the ridges at the peak, which, in turn, sit on the log post.
To fabricate the bent, we first isolated differences in elevation between the centerlines of each of the posts and used these to generate a centerline plot of the system which we could lay out on the floor. Using lasers allowed us to set the bastard valley in space and then place the posts above the valley and in space as well. Once everything is in space (this phrase describes the process of placing all the timbers in a particular system on an imaginary center line plane, perfectly level and plumb over their specific locations. The utmost care must be used when placing timbers in space as any deviation from perfect here will send waves of imprecision through the entire fabrication).
Once the posts have been scribed into the valley and the entire system is place back in space, we can then place the intermediate timbers (tie, small post, and knee brace) in space above the bent and then scribe them into the system.
As this timber frame design has so much interconnectivity, especially at the main peak, where 10 bearing points all center out at one single center line, the degree of precision required to ensure that all of the various systems fabricated in isolation based off of the computer theoretical (theo) perfect actually go together correctly is extreme. A small error (we live in the world of 1/32″‘s for example) can propagate through a timber frame and cause endless deviations from theo. One can never let their guard down and we endlessly check each others’ layout before cutting.
