How to Use Trim Routers

Setting Up

• Like all routers, most trim touters have two depth adjustments. After you loosen a clamp, the base slides up and down for a rough adjustment and, after you lock the clamp, you can do a fine adjustment by turning a screw. You usually need to slide the base up as far as it will go to install the bit, which you do by loosening the collar nut with a wrench, inserting the bit and tightening the collar. After you adjust the depth, you're ready to plug in the machine and start routing or shaping.

Trimming Laminates

• When you trim laminates, you need a trimming bit, which has a straight, close-set blade and a collar that prevents the bit from cutting past the edge. You need to move the router in the opposite direction to the bit rotation so that the bit cuts into the material. Since the bit rotates clockwise, this means moving the machine from left to right -- or counterclockwise around the workpiece. It's never a good idea to back up, because the router can spin out of control, but if you keep it moving steadily forward, it's difficult to make a mistake.

Shaping Edges

• You can use a number of shaping bits with a trim router, including chamfers, round-over and coves. The depth adjustment controls how much of the bit contacts the wood, and setting the base close to the end of the appropriate bit allows you to shape short angles or partial curves. Even though you can control a trim router with one hand, it's still a good idea to clamp the work to the bench and to guide the machine with both hands. One of the features of a trim router is that it has a small base, making it easier for you to keep your eye on the work at all times.

Cutting Mortises and Grooves

• Routing mortises for hinges or locks is easier if you follow a template, but it's possible to follow a well-drawn outline, especially with a trim router. The machine's fine adjustment ensures the correct depth. Some machines come with a plunge base that allows you to rout inlays; set the machine over the area to be routed, then turn it on and push down to plunge the bit into the wood. When you want to rout grooves, either use the edge guide that comes with the machine or clamp a straightedge along the wood to act as a guide.