The 21st Century learning experiences gained as the community, school and businesses design, plan and build a 32 foot long Town Lattice Truss covered bridge for the Village of South Wayne, Wisconsin.
Sunday, March 20, 2011
A full sized assembly fixture ...
Yes a "full sized" (this will be music to some that may feel there has been far too much scale model work up to this point) assembly fixture will be in order to position the rough sawn roof rafter pieces. I will say that IF I knew what I was doing I probably could go right to the real thing and "cut away", as they say! So if you know what you are doing, step up, bring your own wood and cut away. If you are like me follow along and keep tuned, slow but sure, and steady as she goes.
In the close-up above you can see some of the layout lines. The yellow square represents the top truss chord (top plate in house construction) The red line is the Centerline of the Secondary Rafter (this will act as a brace to the truss) it goes below the top chord. The black line shows the edge of this 2"x6" piece. At the end of I have drawn in the Wall Cleat and Seat that will be fastened to the truss web.
Here are the Secondary Rafters. Notice the cuts at both ends. Now getting to this point is no accident and not for the faint of heart. Most are not going to appreciate the math, calculations and work with our "friend", Mr. Framing Square required to get this done.
For now the pictures will have to do. The details will follow, so get some rest. You will need your calculator, pencil and paper. Or maybe you can just Google it?