The router is the most versatile power tool available to the woodworker and its usefulness is enhanced when it’s used with router bushes, which enable almost any ordinary router bit to function as a bearing guided cutter.
Two different types are available: firstly the metric, American style, UJK Technology brass router bushes which will be used in this article. The second type is a stainless steel version, which can be purchased singly or as a set. The stainless steel bushes locate into the 60mm recess which is common on the base of many routers; if not, the UJK Technology sub-base must be used.
Both types of router bushes are used identically, but each is held in the machine in a different way.
What you'll need
Clip the adaptor plate into the base of the router.
Select the appropriate bush and locking ring.
Insert the bush into the recess in the router base and secure it in place with the locking ring.
When using a router bush, there will always be an ‘offset’, which is the distance from edge of the cutter to the outside (or bearing) edge of the bush. For example, when a 20mm bush is used with a 10mm cutter, the offset is 5mm (20-10÷2). The dimensions given for each bush on the inside of the box lid also allow you to calculate the offset with different cutters, as seen from the chart.
In conclusion, changing the offset by using a different cutter/bush combination expands the versatility of the router and enables it to be used in a variety of unique ways.