I used an Amana 72 degree V router bit to cut the Purpleheart halves. I set my bandsaw table to 18 degrees, and cut the edge of a Yellowheart board that was face and edge jointed, and planed. Then I used the jointer with the fence at 72 degrees to smooth the cut edge. I advanced the fence on the band saw to give me the correct length facet, plus the width of the blade kerf. The jointed edge of the yellowheart board always registered to the bandsaw fence, so the diamond is really the cutoff piece. I have a 1″ Starrett 2-3 skip carbide blade on the bandsaw, which gives an incredibly smooth cut, so one facet of the diamond is pretty much as it came off the blade. (I couldn’t get any life out of carbon blades, so I splurged for the Starrett. It was only $1.30 an inch from a local distributor, and it resaws so very nicely through hard maple. The only tablesaw work was after the final glue-up to trim and square the sides.
I used a Wixey angle gauge to set the bandsaw table, and the jointer fence, close to the angle I wanted, and then I used a TS-Aligner Jr. to get the angle as close as I could. www.wixey.com and www.ts-aligner.com
I’m fortunate to have some nice tools and measuring equipment, and I actually believe that making the two cutting boards improved my skill set. I was a Navy fighter pilot, and as an instructor pilot would tell a student an altitude, direction, and airspeed that I wanted them to fly. They always thought that was stupid, and they wanted to try some high performance maneuvers. “After you show me straight and level.” Sometimes it would take 5 to 10 minutes for them to be able to get to the stated conditions. 36,000 pounds of thrust and a high-performance airframe takes some skill, and practice to control. The same with our shop tools. We need to be able to machine boards flat, cut straight lines, and make solid glue joints before we’ll be good at loops and barrel-rolls. But, I know I’m preaching to the choir.