Routing perfect slots

For arrow-straight slots with crisp, clean ends and edges, let your router table, a few shop-made accessories, and a little know-how help you produce on-target results.

Perfect slots

Drilling end holes and sawing out the waste between them is one way to form a slot. But success depends on your unwavering ability to follow the straight cutlines connecting the end holes with a scrollsaw or jigsaw. Here's a better method that eliminates the risk of wandering off course.
1. Lay out the slot

Draw slot boundary lines on the part, extending the end lines to the edges.
2. Position the fence

Chuck a slot-size bit in the router. Place the fence to center the bit in the slot.
3. Set the right stop

Align the slot left end line with the left edge of the bit. Position and secure the right stop.
4. Set the left stop

Align the slot right end line with the right edge of the bit. Position and secure the stop.
5. Add an auxiliary guide

Using the part width to gauge the distance, clamp an auxiliary guide parallel to the fence so the part slides easily between the guide and fence.
6. Drill out the waste

Using a bit ¹⁄₈ " smaller than the slot width, drill overlapping holes inside the layout lines. Drilling an undersized rough slot lets you rout a clean finished-size slot in one easy pass.
7. Make a plunge cut

With the right end of the workpiece touching the right stop, lower it onto the spinning bit.
8 Rout the slot

Feed the part to the left until it hits the stop. The auxiliary guide keeps the part in line.