adjacent inside edge 24 thus the router 71 moves freely about the template 11 on the top surfaces 21 further in this regard the offset 43 of the bar member head end 30 is pointed out as to placement of the hole 61 and wing nuts 66 in a position spaced a distance outwardly from the inside edges 24 to permit the router 71 to be freely guided by the inside edges without encountering interference at the inside corners when the router freely passes by the wing nuts referring now to fig8 there is illustrated a sample guide member 80 having a pie shaped body member 81 with curved outer surface 82 flat top surface 83 flat bottom surface 84 flat interior edges 85 and 86 disposed at a ninety degree angle to each other and an l shaped tongue member 87 disposed centrally of edges 85 and 86 and projecting outwardly therefrom body member 81 has a thickness corresponding to the distance between surfaces 21 and 23 with tongue 87 adapted to be received in the inside corners defined by adjacent ones of the bar members 12 15 such as between bar member 12 and 14 as designated generally by reference numeral 88 with edges 85 and 86 engaging upper guide surfaces.