I'm planning to build a simple plywood bookcase and I need a router for cutting dados. I'm trying to figure out how to accurately determine the distance from the center of the router's collet to the edge of the baseplate. My idea is that knowing this measurement would help me set up a guide or fence correctly for running the router through the dado line. For instance, with my circular saw, I know how far the blade is from the foot, allowing me to position a guide accordingly. However, I can't find this information for the routers I'm considering. Am I missing something about how routers work, or is my terminology off?
3 Answers
Check out this quick video! It shows a method for creating a spacer that helps you find the exact distance between your router base and the cutting bit. While it’s for circular saws, the concept applies to routers too. [Watch here!](https://www.youtube.com/watch?v=H3R856PUt1c)
Just an FYI, the distance from the collet to the edge of the base can shift based on the bit you choose, so there's no fixed spec for routers. My approach is to use a piece of scrap wood with a guide rail for trimming. It makes aligning everything much simpler and gives consistent results.
If you're using different bits, it's best to just measure the distance for each one. The cutting distance can vary based on the bit size and style, so a simple measurement is your best bet. It ensures accuracy every time you switch bits.

I love these kinds of tutorials! It's so much easier to grasp when someone explains the reasoning behind their technique.