Improved Router Dado Jig

[Greg Guarino]

Still not beautiful, but it should be a lot easier to use now, and more accurate as well.

I first made it a couple of years ago when I was building some bookcases. It worked pretty well, but with a couple of flaws.

Firstly, apparently plywood, even oak ply (made, not in China, but in the Great White North) even from the *same* batch, will not be of uniform thickness. The first iteration of the jig had the two halves simply screwed in. Any "adjustments" meant finding new locations for the screws. This was inconvenient, but got the job done.

Next, the "runners" were not completely straight. I thought they were, but the dadoes were consistently a tiny bit more snug in the middle than on the ends. This too was a small flaw, but it bugged me a little.

I had some spare time today, so I made two improvements. I made the jig adjustable using knobs with threaded shafts that mate with threaded inserts. I set it up so the width of the opening can be adjusted up to a little over 1.5". It feels like the knobs hold the movable half of the jig securely.

Next I trued up the runners. I don't have a jointer, so I used a router with a straight bit and a framing square as a guide. Now both are nice and straight.

[-MIKE-]

Sounds like some great improvements. Here's my take on it...

[Greg Guarino]

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Well, I have to say that yours is more finely done in pretty much every way . But it confused me a little at first; I didn't get how the toggle clamps were supposed to work, especially the first set that were attached to one o f the "halves". But now I see that you changed that, I assume sliding the j ig along the work to each new location.

I remade mine more to try my hand at using knobs to make an adjustable jig. It turned out to be pretty easy. It looks like your knobs have a female th read that mates with a T-bolt. I used knobs with male shafts that mate with threaded inserts that thread into the wood. The connection seems solid, bu t I guess I'll learn if that's really true over time.

I haven't used the "new" jig yet, and don't in fact have a project planned using dado joints at the moment. But I have pictures from other projects, w ith earlier iterations of the jig. I use mine a little differently. I screw the jig into a sacrificial work surface. The jig stays stationary; I slide the workpiece under it and clamp it at each location to the work surface.

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Thanks for the link. It's given me some ideas about how I might make the ne xt one better. (you know, someday, when I have more time) :)

In this case I had two pieces (temporarily) fastened side by side so I coul d do both together: saving time and ensuring that they'd have to line up. I realized while doing that that a longer jig (like yours) would have been a better idea.

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[Leon]

I designed this about 11 years ago. It adjusts to the width of the board, is portable, and self squares to the board.

[Greg Guarino]

There's a design I haven't seen before, and unsurprisingly, also built much more cleanly than mine.

I'm curious. Why do you need both sides to be snug to the work? Is that to make doubly sure the jig is square? When you're doing narrow stock, as in the photo, does the half of the jig that protrudes out toward you get in your way?

I'm also curious about the bottom; I guess you recessed the heads of the bolts into the jig? T-bolts I imagine?

I figure I'll eventually build a new jig entirely, incorporating some of what I've learned from this one. That's why I ask.

Mine "self squares" also, but the guide edge is not as long as I'd like it to be; another detail I noticed *after* I built it. In this photo you can see my solution for long stock:

Note the small block that's clamped to the bench at right. There's another one out of the frame to the other side of the jig. I lined them up with a straightedge before I started making the cuts. I'm not sure it was necessary, but it made me feel better about the alignment, and made it quick to change from one location to the next.

I also found it convenient to stick a piece of 3/4" scrap in one of the dadoes (the black triangular piece in the photo). That gave me a convenient "handle" to tap with a mallet to get the placement exactly right. The uprights in the photo were something like 80" long, so the ends of the boards were out of reach for many of the cuts.

[Leon]

Basically yes, snug it on both sides to help keep it square, and no nothing gets in the way.

Carriage bolts. No need to recess as that portion is never in to tact with the work.

Not a problem, that's why I posted the pics. :-)

This jog was first designed to use a guide bugging and straight bit, hence the note on the jig to keep the router clocked in a certain direction. I later modified it to use a short top bearing fluff cut bit.

[Leon]

Too many type'os to correct. ;~) Thank you iPad for all of that.

[DerbyDad03]

My "favorite" iPad auto-correct:

it's not ----> it' snot

I'm anal (but not perfect) about proper typing in texts, etc. so I always m ake sure that I use apostrophes where appropriate. Unfortunately, the iPad does better without them, usually auto-correcting and adding the apostrophe if I leave it out. The thing is, I'm used to typing the apostrophe and for some reason the iPad loves to auto-correct "apostrophe s" by moving the s to the beginning of the next word, sometimes retaining the next word, somet imes changing it. That sometimes results in some pretty strange sentences.

It's cold ----> It' scold That's bad ----> That' shad (is that Shad the rapper or Shad the fish?)

[Leon]

And if you think that is bad try dictating to the iPad! ;~)

[DerbyDad03]

ys make sure that I use apostrophes where appropriate. Unfortunately, the i Pad does better without them, usually auto-correcting and adding the apostr ophe if I leave it out. The thing is, I'm used to typing the apostrophe and for some reason the iPad loves to auto-correct "apostrophe s" by moving th e s to the beginning of the next word, sometimes retaining the next word, s ometimes changing it. That sometimes results in some pretty strange sentenc es.

This unedited response was recorded onto my iPad using the Dragon applicati on. I don't know how it will come out because I don't use the application v ery often. When I am done recording I'm simply going to copy and paste it i nto rec.woodworking to see how it comes out. If it comes out good that's wh at you see, if it comes out bad you'll see that also. I'm now going to end the recording. Let's see how it came out. I wish me luck.