Router Basics: Feed Direction, Bits, and Setup

A router is a motor that spins a cutter and nothing else. Everything that makes it useful, and everything that makes it dangerous, comes from how the cutter meets the wood. Get the feed direction right and the tool is stable and predictable. Get it wrong and the router tries to travel on its own, usually across the surface you were shaping.

Feed Direction Is the Whole Safety Story

The bit spins clockwise when viewed from above the router. You want to feed so the wood pushes back against the cutter rather than being dragged into it. On the outside edge of a board, held with the router on top, that means moving from left to right. The resistance you feel is correct and it is what keeps the base against the work.

Inside a frame, a cutout, or any aperture where the bit is enclosed by the workpiece, the direction reverses: you move right to left. The rule has not changed, only the geometry. The cutter is now meeting the opposite face of the wood, so travelling the other way keeps the same resistance.

On a router table the workpiece moves instead of the tool and the bit spins counter-clockwise from the operator’s side, so stock feeds right to left against the fence. The principle is identical.

If you ever cannot work out the direction, stop and trace it. Mark the rotation on the workpiece with an arrow and feed so the cutting edge meets the wood before the wood meets the cutting edge.

Climb Cutting

Climb cutting feeds in the same direction as the rotation. The cutter grabs and pulls the router forward, which is exactly what you spend the rest of your time preventing. It survives as a technique because it produces a cleaner cut in wild or reversing grain, where conventional feed lifts fibres and tears them.

Use it as a light finishing pass and nothing else. Take a whisper of material, keep a firm grip with both hands, and never climb cut with a large-diameter bit or on a narrow piece that offers no support. On a router table, climb cutting freehand against an unfenced bit can throw the workpiece, so it belongs only in a controlled setup with hold-downs.

Choosing a Bit

Bits divide into three families by what they do rather than what they look like.

Shank diameter matters more than most beginners expect. A larger shank flexes less, which means less chatter and a smoother surface. Where a bit is offered in both sizes and your router accepts the larger collet, take the larger one.

Carbide-tipped bits hold an edge far longer than plain high-speed steel in sheet goods and hardwood. Solid carbide spiral bits cut cleanly in plywood because the shear angle slices rather than chops, and an up-cut spiral clears chips upward while a down-cut spiral presses the surface fibres down and reduces tearout on the top face.

Setting the Bit in the Collet

The collet is a split sleeve that squeezes the shank. It grips over its whole length, so a bit inserted only partway is held by a fraction of the surface it was designed to use.

Slide the shank in nearly all the way, then pull it back a small amount so it is not resting on the bottom of the collet cavity. Tighten with the wrench, not by hand. A bit that bottoms out can be pushed deeper by vibration during a cut, which changes the depth mid-pass.

Keep the collet and the shank clean. Pitch and dust in the collet stop it closing evenly and are a common cause of a bit slipping in a tool that seems otherwise fine.

Speed and Bit Diameter

Router motors offer a speed range, and the reason is bit diameter. A cutting edge on a wide bit covers much more distance per revolution than an edge near the centre of a small one. Run a large panel bit at the speed suited to a small roundover and the edge is moving fast enough to burn the wood, dull the carbide and load the bit beyond what it was built for.

Large bits are marked with a maximum speed by the manufacturer. Set the router to that or below. Where the router has no variable speed at all, large-diameter bits do not belong in it.

Depth of Cut

Almost every routing problem that is not feed direction is depth of cut. Removing a deep profile in one pass overloads the motor, burns the wood, and makes the tool difficult to steer.

Take the profile in stages, lowering the bit between passes and letting the last pass be light. A final shallow cut removes the marks of the heavier ones and leaves a surface that needs little sanding. In a groove, the same logic applies with an added reason: a deep slot traps chips, and trapped chips burn.

What People Get Wrong About This

The most common mistake is routing an edge that is already the finished edge and expecting the bearing to fix a wavy line. A bearing-guided bit follows the surface it rides on exactly. Every bump and hollow in that edge is copied into the profile. Straighten the edge first, then shape it.

The second mistake is starting the cut in the middle of an edge. Enter at the end of the board wherever possible, so the base is supported and the bit is not plunging into the centre of a surface it has to climb out of.

A third is trusting the depth stop without a test cut. Depth stops drift, bits sit at slightly different heights after a change, and a joinery bit set from memory will be wrong. Cut scrap of the same thickness first.

And the last is routing small pieces freehand. A workpiece that cannot be clamped cannot be routed safely by hand. Put it on the table, use a sled or a hold-down, or make the part from a longer piece and cut it to length afterwards.

Grain and Tearout

End grain tears more readily than long grain, and the tear happens at the exit of the cut. Route the end grain first and the long grain afterwards, so the long-grain pass removes the torn corner. On a four-sided profile, that means the two ends before the two edges.

A backer block clamped at the exit of a cut supports the fibres and stops them breaking out. It costs a minute and saves a part.

Dust and Noise

Routers throw a great deal of fine dust and they are loud enough to damage hearing over a session. Connect the dust port where the router has one, wear eye protection because chips leave a bit at speed, and use hearing protection as a matter of routine rather than for long jobs only.

Clear chips from a groove between passes rather than letting them pack. Packed chips rub, and rubbing is what burns.

Where to Go Next

The router is a joinery machine as much as a shaping one. Dado and rabbet joints are among the cleanest cuts it makes, and a straight bit with a guide is often more accurate than the same cut on a table saw. For edge treatments that will be finished, plan the profile around how wood movement will affect the part once it is assembled.