Simple Router Dado Guide for Perfectly Placed Cuts
A router and straightedge guide make a great combination for cutting dadoes and grooves. The straightedge keeps the router traveling in a straight line, helping produce clean, accurate cuts.
But there's one frustrating part of the setup: figuring out exactly where to position the guide.
Since the router bit is offset from the edge of the router base, you normally have to measure that distance and account for it when positioning the straightedge.
And even after measuring carefully, it's easy to wonder whether the dado will end up exactly where you want it.
This simple router dado guide eliminates the guesswork by adding a small alignment board to your straightedge.
Once it's set up, you can position the guide directly from your layout marks without measuring the router's offset.
Add an Alignment Board to Your Router Guide
The idea is straightforward.
Attach a small alignment board to your straightedge guide so the board extends across the router's cutting path.
The alignment board needs to be positioned square to the straightedge.
Once it's attached, you can use your router to cut a reference dado directly into the board.
This dado shows exactly where the router bit will cut when the router base rides against the straightedge.
It's a simple way to turn an ordinary straightedge into a more convenient dado-routing guide.
How to Set Up the Router Dado Guide
You only need a straightedge guide, a small piece of wood, and the router bit you plan to use.
Step 1: Attach the Alignment Board
Start by fastening the alignment board square to the straightedge guide.
Make sure it's secure and won't shift during use.
The board should extend far enough into the router's path to allow you to make a short reference cut.
Step 2: Rout a Reference Dado
With the router unplugged or disconnected from power, install the bit you'll use for the project.
Position the router base against the straightedge.
After securing the guide and supporting the alignment board, make a shallow dado across the board.
The cut establishes the exact relationship between the router bit and the straightedge.
Step 3: Align the Guide with Your Layout Marks
Now the setup becomes much easier.
Instead of measuring the distance between the bit and router base, simply position the straightedge so the reference dado in the alignment board lines up with the layout marks on your workpiece.
Clamp the straightedge securely in place.
With the router base riding against the guide, the bit will follow the same cutting path established by the reference dado.
Step 4: Rout the Dado
With the guide securely positioned, rout the dado using the appropriate cutting depth and feed direction.
For deeper dadoes, make multiple shallow passes rather than trying to remove all the material at once.
The straightedge keeps the router traveling in a straight line, while the alignment board helps ensure the cut starts in the correct location.
A Simple Way to Improve Router Accuracy
The best woodworking jigs often solve a common problem without adding much complexity.
This router dado guide is a good example.
By adding a small alignment board to a straightedge, you eliminate the need to repeatedly measure the router bit offset.
Just line up the reference dado with your layout marks, clamp the guide in place, and make the cut.
Shop Tip: The reference dado is accurate for the router, bit, and base orientation used to create it. If you change bits, switch routers, or alter how the router rides against the straightedge, make a new reference cut.
It's a small addition to your router setup that can make cutting accurate dadoes and grooves a lot easier.
Router Joinery: Simple Techniques for Stronger Woodworking Projects
A router can do much more than shape decorative edges. From dadoes and grooves to splines and other joinery, the right techniques make it easy to create accurate, strong connections. Explore more ways to put your router to work on your next woodworking project.
EXPLORE ROUTER JOINERY → Get More from Your Router
