ROUTING'S BEST KEPT SECRET

Denis Lock continues his series on exploiting the potential of the router.

- Denis Lock

In my last article I unveiled what I consider to be routing's best-kept secret: the router guide bush. In this article I will explore further applications of this powerful technique. It is worth repeating my schematic (Photo 1) of the use of a guide bush. The router bit is plunged through the bush (which follows the pattern) into the workpiece. It is obvious that the cutting diameter of the bit must be less than the internal diameter of bush. I normally allow a 6mm difference. The guide bush on my Bosch router has a 17mm external diameter so I settle for a bit diameter of 10mm or less. At a push I will go to 12mm.

Beyond this there is not sufficient space for vacuum extraction of the dust and chips and overheating occurs. It is also obvious that the bit must cut on its tip. Bits with bearings have no place in this technique. Photo 2 shows a range of standard bits suitable for guide bush routing. Photo 3 shows three special plunge-cutting bits that can be used with a guide bush. Typically these are used to rout patterns on door (Photo 4) and other panels. This pattern can be termed an outline pattern. Care must be taken to keep the guide bush riding on the pattern. Any movement away from the pattern ruins the result.

I have made a number of patterns to rout outlines. I have used a guide bush to pattern rout the outline of a bunny on a child's toy box. I have pattern routed the outline of a wine glass on a countertop wine stand. I have pattern routed the outline of a heart on the lid of a jewellery box. This pattern was used twice to rout a pair of interlocked hearts. This was one of the best Valentine's present I have made.