This 3D model was originally created with Sketchup 13 and then converted to all other 3D formats. Native format is .skp 3dsmax scene is 3ds Max 2016 version, rendered with Vray 3.00 Router Centering Jig.
Cut the 'red' piece with your table saw... precicely at the line made with your centering bit.
Because the board is 6wide, add two 3 blocks beyond 'red' piece. Set fence here for center flute.
Both outside flutes are made when
two 4blocks replace the aforementioned 3 blocks when fence is reset. (Please RATE this model. Thanks)