Start with a safe setup
A router spins a bit at very high speed, so most good technique is really about control. Before anything else, put on eye protection, hearing protection and a dust mask, since a router throws chips and fine dust in all directions. Read the manufacturer’s manual for your specific router, because collet depth, plunge locks and speed controls differ from model to model. The section on hearing and dust protection in a general safety guide is worth a look if your kit is thin.
Always unplug the router, or remove the battery on a cordless model, before changing a bit or adjusting the base. Many accidents happen during a “quick” change when the switch is bumped. Plan to keep both hands on the handles during the cut, and clamp the workpiece so it cannot slide. Good workholding systems matter more with a router than with almost any other handheld tool, because the cutter pulls on the work as it spins.
Seat the bit correctly
Insert the shank fully into the collet, then back it out a small amount, often around a sixteenth of an inch, before tightening. Bottoming out a shank can make it harder to release and can leave the bit sitting unevenly. Use a collet size that matches the shank (for example, a quarter-inch shank in a quarter-inch collet) rather than forcing a mismatch. Tighten firmly with the wrenches that came with the tool.
Check the bit before every session. Look for chips in the carbide, bent shanks, and any wobble when you spin it by hand with the power off. A damaged bit should be replaced, not used.
Understand feed direction
Most routers turn the bit clockwise when you look down on the tool from above. The bit cuts best when it meets the wood moving against that rotation, so you feed the router in the direction that the bit’s cutting edge is traveling toward you. In practice:
- On the outside edge of a board, move the router counterclockwise around the piece.
- On inside edges, such as the opening of a frame or a cutout, move clockwise.
- On a router table, the stock is typically fed from right to left as you face the fence.
Feeding the wrong way is called a climb cut. The bit can grab the work and pull the router forward faster than you intend. Some experienced woodworkers use a very light climb pass to limit tear-out on difficult grain, but it is easy to lose control, so beginners are usually better off avoiding it entirely.
A steady, even pace gives the cleanest surface. Too fast leaves a rough, wavy edge and strains the motor; too slow, or pausing in place, tends to burn the wood. Listen to the motor: a steady tone suggests a good rhythm, and a bog down means ease off the pressure or take a lighter cut.
Take shallow depth passes
Cutting a deep profile in one pass is hard on the bit, the motor and your hands. It is usually better to remove material in several light passes, lowering the cutter slightly between each one. The right amount varies with bit diameter, wood species and tool power, but for a hardwood groove many woodworkers take passes of roughly a quarter inch or less, and go shallower with large-diameter bits or dense wood. The final pass can be very light, which leaves a smoother surface that needs little cleanup.
Understanding wood grain helps here. Cutting across end grain tends to splinter the far edge as the bit exits, so rout end grain first on a board and then do the long edges, which will clean up any small breakout at the corners. A scrap block clamped behind the exit point also supports the fibers.
Match speed to the bit
Large-diameter bits carry more edge speed at the same revolutions per minute, so they generally need a slower setting than small bits. Variable-speed routers let you adjust this, and the manual or the bit packaging often suggests a range. If you are unsure how tool RPM relates to cutting quality, the general principle is that too fast produces heat and burning, while too slow can leave a rough surface or chatter.
Keep bits clean and sharp
Pitch and resin from wood build up on the cutting edges and cause friction and burn marks, even on a bit that is still sharp. Remove the bit when it is cool and unplugged, and clean it with a cleaner made for the purpose, using a soft brush rather than a metal one. Do not scrape the carbide edge with a hard tool.
Store bits so the cutting edges do not touch each other, in a case or a drilled block. Sharpening carbide bits is usually left to a professional sharpening service, and replacing a cheap bit can make more sense than paying for sharpening. Picking router bit selection criteria carefully up front, such as carbide quality and shank size, helps bits last longer.
Support the router
A router base is small, and tipping it at the start or end of a cut can gouge the work. Keep the base flat on the surface throughout. When routing an edge on a narrow board, clamp a second board of the same thickness beside it to widen the supporting surface. For small parts, a router table with the right fence setup is usually safer and more accurate than trying to hold the piece by hand.
A simple routine for each cut
- Unplug the router and inspect the bit.
- Set a shallow first depth and test it on scrap of the same wood.
- Clamp the work and check the path for clamps or cords.
- Plug in, start the router with the bit clear of the wood, and let it reach full speed.
- Feed steadily against the rotation, then lower the bit and repeat for deeper cuts.
- Let the bit stop completely before lifting the router away from the work.
A test piece costs little and saves ruined parts. Once the settings look right on scrap, you can make the real cut with more confidence.