On the recently released Series 4 DVD, episode 401, we used a 1/2” sub-fence over the regular table mounted fence and changed a 3/4” dado to a 1 1/4” in seconds without any bit changes! Today’s tip will take that principle one step further.
How often have you found yourself spending time and money hunting for a metric router bit to suit that weird sized plywood they sell these days?
Well folks, that’s a thing of the past. Using today’s tip you’ll make any sized dado with your existing router bit.
Making The Sub-Fence
Our sub-fence has two different sides; one accomodates 17.08 mm plywood and the other fits laminated plywood 19.22 mm. Now try finding these bits down at the local hardware! We used a 1/2" straight router bit and two different offset blocks to obtain the exact sized dado's for our projects.
Plane a piece of hardwood to suit your particular application. To check the fit, place it next to the table fence, run a dado, remove the hardwood and make a second pass. If necessary plane another piece until the correct thickness is achieved.
Follow this same procedure for a different application for the opposite side of the sub-fence.
Nail the two pieces to a block the same width as the table fence and you have your very own 18.4267 mm “router bit”. It's simple, easy, frustration free and works like a charm!
We marked the sizes on our sub-fence for future reference.
Making The Cut
We ran a dado to fit laminated stock. Mark the dado location on your stock.
Clamp the table fence with the sub-fence to the router table and run the first dado. The first pass is ALWAYS made using the sub-fence so that the second pass is made on the cutting side of the bit.
Remove the sub-fence and make a second pass.
No taping the fence and hoping it is .2146 mm to the right before making a second pass! No guesswork, just a perfectly snug fit.
Bingo, bango, bongo. . . I'm on to the next project!