Abstract: An attachment for portable routers having a relatively long, rotary cutting tool for imparting decorative contours in relatively non-portable construction components such as staircase railings and the like. A massive block is mounted on a relatively thick base plate and the block, in turn, mounts a cantilevered bearing holder in spaced apart parallelism from the base plate. One end of the shaft of the cutting tool is rotatably mounted in the bearing and the other shaft end is coupled to the router chuck.