Box joints with dado/router decisions

[Michael Merrill]

I'm interested in cutting some box joints, I was going to try to use a cheap dado set I have but they don't cut close to square and flat dados.

So I back to square 1 and can decide what direction to go


I could get the Frued Box cutting blade set at about $70 that would work well for 1/4 and 3/8 joints, but the blade is not useful for general purpose dado.
I could go with a standard good stacked dado set, about $100 and use it for box joints as well. Although when I look at the hook design on the dado blades they don't seem that they would cut very square at the edge?
Move away from the TS and cut box joints using the router table, I already have all the bits that would be needed for this.All three require me to build a sled/jig that is not much different depending on which way I go. Cost is a bit of an option but more important is quality of work, I don't want to build a jig to only have to start over as the quality is not acceptable. If I don't need to throw $70 at a specialized blade set I'd rather not.

What are members thoughts on the different approaches?

[Mike Marcade]

I say router! :D

[Dave Falkenstein]

I have done them both ways, and I find that a router does a better job, IMHO. I have an Incra fence setup for my router table, and that makes box joints a snap because of the easy indexing with the fence.

[Michael Short]

I made a jig like they use on the router workshop except my is made from wood. I used a 1/4" flat stock and cut a slot 1/8" deep using a 1/4" straight bit and installed a 1/4" square dowel rod and sloted it perpendicurar to the dowel for spacing adjustment. I feed the material using a squared scrap block with a handle that has a slot to slide on the dowel for support and ease of sliding the material and will help with chip out.

You can use this jig for making smaller dentil molding as well. I use the the 1/4" bit and space 1/2" for the next cut and 1/8" deep and the use a cove bit on one side for detail.

[Jim Becker]

In lieu of the new dedicated box-joint blades, the router table is likely to give you more consistent and clean results. However, a good sharp cutter of the correct configuration will be the difference between a nice joint and a great one. Don't skimp on the cutter...

[Bill Huber]

I have tried to cut box joints on the saw and even with a good box joint jig I still had problems getting them just right. Set up time was a lot for me.
Then I made a jig for the router table and had the same problem.
I then got a PC 4212 and cut some great box joints with it. Now if I need to make box joints I always us the PC and do really well and they look great.

The first box joint I cut on the PC was a good one and set up is really fast and easy.

[Jared Cuneo]

I'll be the contrarian here :) I prefer the TS since I have a smaller shop and the TS is the central machine. I'll caveat this by saying that my router table is an extension so I don't have a large super flat surface dedicated to the router.

I have cut MANY sets of 1/4, 3/8 and 1/2" box joints using a piece of MDF with the key glued in (I have 3/8" side and flip it over for 1/2" joints). I attach this to the stock miter gauge and use a Freud Dado stack with *excellent* results.

For me, the noise is MUCH lower, better dust collection on *my* setup, and once I mark the joint setup on the miter gauge with a razor, subsequent setups require usually only one adjustment to get perfect.

My .02.....plus, if you have a dado set that won't cut flat or straight, sounds like you need a new set anyway :)

JC

[Jim Kountz]

For me it depends on stock thickness. For 3/8 or less the router is the go to tool but if you're using thicker stock the table saw works alot better and is not so darn noisy. That being said, I agree with Jared saying that if your dado is not cutting square and straight, you need a new set or possibly a new saw. Beware of the cheaper dado sets, they will NOT leave as nice of a cut as a premium set. For me it was a Freud set. I justified the cost since I would also be using it for umpteen others procedures in the shop. Take your time building the jig, research the net and you will find several nice plans. The best results Ive got came from a sled that rides in BOTH miter slots. This method lets you take all the play out of it and keeps it aligned.
Theres my two cents with some change!

[Jeff Booth]

I use a router mounted on a woodrat. Works extremely well. Woodrats are expensive, but they can do certain things very well and very quickly (box joints, dovetails, M&T, stopped dados/dovetails etc.....) and there is 100% flexibility, for example the box joints can be perfectly spaced or any arbitrary spacing so long as one half is at least a wide as the straight bit used. Similar story with dovetails.

My input.

JB

[Jerome Hanby]

I recently went through the same choice. I decided to go with the router. I have a router leaf on my table saw, so I made the box joint jig and screwed it to my table saw miter gauge. I discovered two important things while getting this setup to work right. The first is the spacing between the router bit and the guide pin is critical (my clamping the jig to the miter gauge really messed this up, so i screwed it down after the first botched effort). Second, if you size your project so that you start with a complete pin and end with a complete tail, then you can cut all four sides at once and avoid a lot of potential mistakes. I didn't do this, but I bet if you have a fifth piece of scrap material you can add to the stack, you could avoid the slight splintering I saw on my outside piece.

[Norman Pyles]

I made a jig like they use on the router workshop except my is made from wood. I used a 1/4" flat stock and cut a slot 1/8" deep using a 1/4" straight bit and installed a 1/4" square dowel rod and sloted it perpendicurar to the dowel for spacing adjustment. I feed the material using a squared scrap block with a handle that has a slot to slide on the dowel for support and ease of sliding the material and will help with chip out.

You can use this jig for making smaller dentil molding as well. I use the the 1/4" bit and space 1/2" for the next cut and 1/8" deep and the use a cove bit on one side for detail.

That's the way I did it too. I used MDF for the fixture. I am going to make one out of some kind of plastic when I get time. Very simple and works great.

[Will Blick]

Some great responses....

I agree that the TS method is FAST and much easier vs. a jig. The secret is, setting the "key" at the perfect location, which can be tedious. I have tried a few jigs on the market where you can adjust the key position, but it's trial an error. OTOH, if you have an Incra on the TS, it makes another reliable option.

Incra / router table. Very reliable, if you have a FLAT table and have good memory / recall, as you can't make a mistake on the fence setting. With .001" positioning, you can be quite accurate. Of course, Incra is not the only easy-to-set fence, so not trying to badger their competition here.

Dedicated box joint jig. The Leigh Super Jigs allow box joints with a unique twist. With their new E-Bush, an elliptical bushing.... you can control the width of the cuts down to 1/20k of an inch. This is what Matt told me at a ww show...but yet their literature claims less....it varies throughout their web site. Anyway, the benefit here is, you can really fine tune the fit with this bushing.... a little trial and error, but overall this method has the potential to be the most accurate. Of course, I have not tried this yet, cause Leigh is not shipping my Finger joint jig and bits till late Jan. now....

[Andrew Shaber]

I do mine on the TS with a fairly cheap dado stack. My Jig has a few key features.
1. it has a bottom board so the workpiece is not riding across my throat plate and moving
2. the backing board acts as a ZCI preventing chipout. The closer the match the better the result.
3. I clamp the jig to my incra 1000 fence. Then I use the tightening knobs to fine tune it.
4. I find it critical to hold the workpiece with the same pressure against the key for each cut.

[Jerome Hanby]

I do mine on the TS with a fairly cheap dado stack. My Jig has a few key features.
1. it has a bottom board so the workpiece is not riding across my throat plate and moving


That's a great idea, I was constantly getting "hung" on my router's insert plate!