I needed a router trammel for a current project. I had made some router skiis using Harry's plans. I attached a wood block to a router ski and drilled a hole in the block for the pivot pin. I used threaded rods for my skiis which made it easy to adjust the trammel to exact length. Because of the rod slots in the ski the router base thickness is infinitely adjustable. Took me a couple of minutes to attach the wood block. Worked perfectly. Thank You again, Harry.