I’ve got an upcoming bookcase build that has me a little on the fence in regards to the joinery. One of the main reasons I use pocket holes for most of my projects is it’s a way to create strong joints quickly. That’s is great for me considering the time constraints of making a project and video pretty much every week. But due to the size and the angles in which the shelves will be visible I’m not entirely sure that pocket holes will be appropriate for the bookshelves….maybe, maybe not.
The other joinery method I was contemplating was just regular rabbets and dados. I’ve got a dado stack for my table saw but setting it up to exact thickness of wood is a bit of a pin in the rear. And cutting dado’s in the middle of longer planks doesn’t sound too fun either. The other option was to use a router and a router dado jig.
There are many router dado jig options out there. I could have very easily just made one of them but I wanted to be a little different with this one. Just for the sake of trying something new. My spline jig and miter sled were each made from a single 2′ x 2′ piece of plywood so that’s the route I went with this one. I designed the project in SketchUp first to make sure I could get everything from the 2′ square piece of plywood. Another thing I wanted to do was to eliminate the need to cut any slots. So step one was to follow my layout diagram.
Six cuts later I had all of the rip cuts done and laid out on my work surface according to the layout diagram.
Then it was on to the crosscutting. I used my table saw for this instead of my miter saw as some of the pieces were a little small. A magnetic base works great as an adjustable stop block by the way!
And of course a stop block can be used on the sled itself when needed. I prefer the one sided crosscut sleds on the table saw. It keeps you to one side and away from being directly in line with the blade.
Finally all the parts are cut to size. It’s just a bunch of rectangles. Nothing complicated.
To assemble the jig I used wood glue and some 5/8” brads to hold everything in place. The brads aren’t there for strength, just to hold everything while the glue dries.
For some reason I see a lot of feedback online from others saying they don’t like to cut slots in their jigs. I designed this so that it uses a hold down block to grab a floating guide. That way there is not slots to cut. A couple spacer blocks are needed to get to the appropriate thickness for the hold down blocks.
Holes are then drilled into the hold down block and what will be the tightening nut. No, my logo isn’t photoshoped onto my drill press fence. I “branded” it there with my toner transfer method.
The simplest way to make a hold down nut is to drive a t-nut into a rectangle. So that’s what I did.
The built up spacer blocks are the same thickness as the floating guide so a little material is removed with a sander. This will allow the hold down blocks to create a little bit more clamping pressure.
To give the hold down blocks a little bite I glued sandpaper to them. I just used a random orbital sanding disk which already had the appropriate size holes for the carriage bolts I was using.
I sized the router guides to have 3” of distance from the fence to the zero clearance line. That should be enough for most routers using a 1-2” router bit. With a 1/2” bit installed in my router the distance from the edge of the bit to the end of the base plate is 2-3/4” so I needed to cut a new zero clearance edge on both guides.
The fences will be below the router guides and the front fence needs to be perpendicular to the stationary guide. That way only one reference mark is needed on the work piece to establish the location. Wood glue and brads will hold it in place.
The second fence doesn’t necessarily need to be perpendicular. It just needs to allow enough room for the floating guide to move freely. Again, wood glue and brads to hold it while the glue dries.
I used hardware that I already had on hand which was 5/16” x 3-1/2” carriage bolts and matching t-nuts. You could probably get away with a smaller diameter bolt and wing nut.
To set the width of the dado insert the material that will be going into the dado into the jig. Adjust the floating guide to sandwich the material. And tighten down the hold down blocks.
Clamp the jig to the work piece and route a dado. The resulting dado should be nice and tight. To allow for a slightly looser fitting dado you can use a piece of paper or two added to the material thickness when adjusting the jig.
The results are perfect every time, regardless of what material thickness you are working with. I designed this to work with material from 1/2” up to 1-3/4” in thickness.
There are many dado jig options out there. If you would like to build this one click here to download the cutting diagram. It’s not a step by step tutorial as the build is pretty easy to follow with the video and this article. It’s just the layout diagram. EDIT: I just added a metric version with millimeter dimensions. Click here for the metric version.