Have a commission to build, involving M&T...

[dbhost]

I have been voluntold that I am going to design and build a wooden dog crate / end table for our dog so that the giant, ugly plastic thing can be banished to the attic or a yard sale. (She wants to keep it for transport, I am not wild about that idea...).

So I did my research, found some examples, took the good, threw out the bad, and whipped up, at least partially, still working it, but whipped up a design for a dog crate / end table in Mission style. The build will be a bit non traditional though using walnut as the primary wood, and either maple or pecan slats.

Now the big problem, M&T joinery. I have done plenty of mortises, but am not sure I am doing my tenons "right"...

I have been using the dado stack to cut my tenons. I can make the face and cheek cuts at the same time with it, I just rotate the stock 90 deg, make my next pass, until done... But is that right? The problem I get is I end up having to sneak up on the tenon size and it takes a LOT of passes soemtimes, just ekeing the blade up just a shave more until the thickness is just right...

Is there a better way to do this?

[atgcpaul]

I'm not quite sure I understand your method. Typically the "face" and the "cheek" are synonymous. Do you mean face and shoulder?

Anyway, to get to my final tenon thickness (and assuming the mortise is in the center of the board), I lay that board next to the dado stack and raise the blade until the height of the blade is just shy of the mortise opening. After that I always have to sneak up on the tenon thickness with my dado stack. Once it's dialed in, I lock the elevation wheel and cut them all at the same time. I actually have a heavy duty tenon jig to cut them Norm style but have never used it; I've always used the dado stack.

All of my M&Ts are done with the router and slip tenons now.

[dbhost]

Okay say for example I am building a table with 2" legs, and 3/4" stretchers. I want the joint smack in the middle of the leg width, and I am using a 1/4" thick tenon.

Assuming I have the stock jointed / planed to exactly 3/4", I raise the blade just sky of .25, and make my passes, test the fit of the tenon on the joint, which I expect to not go, then sneak up until it is a nice tight fit...

My mortises are cut with an HF mortiser, lazy easy... Just make sure I cut inside the scribe lines...

[JR]

One of the first jigs I ever made was a tenoning jig that fits on the BT3K fence. Couple that with a microadjuster and it's pretty easy to sneak up on the cheeks.

I will say, though, that you will likely have to do some fine tuning. A shoulder plane would be helpful, or a sharp chisel. Sometimes you might need a sliver of wood to replace an "over adjustment" - DAMHIKT!

[atgcpaul]

Yep. Sounds about the same as what I'd do. I would make my tenon thicker, though, maybe 3/8" or even 1/2" since your legs are so much thicker and there's no real risk of blowing out the mortise.

[LCHIEN]

cutting both sides of a tenon is the perfect way to keep them centered.
A hazard occurs because for each 1/32nd you adjust the blade in you get twice that, e.g. 1/16th reduction in thickness of the tenon. So you have to be extra careful in making adjustments as you make what you think is a small adjustment and suddenly its a lot looser than you think.

MY preferred method of sneaking up on the tenon size would not be so much to sneak up.
I would use my digital calipers to check the size of the first cut on the tenon then check the size of the mortise. Measure the difference and divide in half - this is the perfect height adjustment.
Now raise the BT3000 blade, the key here is that there is a 12 thread per inch drive screw so each turn is 83.33 mils; you can note the position of the knob so make quarter turn adjustments; 1/8 turn is possible. THis is quite accurate and repeatable, I've measured before. So each quarter turn is 21 mils. a hair over 1/64th inch. Divide the amount of adjustment you need in mils by 21 (a $6 four function calculator is handy to keep by the saw for this) and count off the number of half turns. If you are cobservative, do one less quarter turn than you think you need to get a interference fit or a chance to make one more adjustment. There's a little backlash in the BT3000, try to advance in one direction only and don't back up, but in the long haul its ok.

Make a trial run and prove to yourself that this works well. No more sneaking up. Just jump straight to the answer.

[dbhost]

Yep. Sounds about the same as what I'd do. I would make my tenon thicker, though, maybe 3/8" or even 1/2" since your legs are so much thicker and there's no real risk of blowing out the mortise.

That's not a terrible idea... Sure would give my HF mortiser a workout!

I am getting to think that I am maybe doing it maybe not perfectly, but in a reasonable fashion.... And yeah it is the too far adjustments I am worried about... In the past I simply hit it with the sander for a quick second just nudging enough off when I was in the just barely but not quite fitting category...

[mpc]

Sounds like you are doing it in a reasonable and safe method. TV shows never show you the adjustments and number of trials it took to get the tool adjusted... they make it look like you should be able to set-it-and-go quickly. ha.

Flipping the workpiece over guarantees a centered tenon. Also, while doing the initial blade height adjustments, just cut about a 1/4inch piece of the tenon - no need to run the whole cheek surfaces after each adjustment. If you go to far during the adjustment, only the last bit of the tenon will be too thin; most of it will still be okay so the joint should be reasonably strong. Once you've got the blade set, then run the rest of the tenon.

If you do raise the blade a tick too far, the backlash in the blade height mechanism will rear its ugly head making it hard to just barely lower the blade. An easier way to "back off just a bit" is to apply tape or use paper spacers on the SMT to raise the workpiece by whatever you need to lower the blade. If your workpieces aren't all exactly the same thickness, a stack of shims/spacers lets you sneak up on each individual tenon's thickness without touching the blade. Just set the blade a tad high (too thin a tenon), stack several shims to compensate, and make a test tenon cut. Too fat a tenon? Remove one shim/sheet of paper and re-cut. Next tenon: re-stack all the shims and make a too-thick tenon again and remove one shim at a time.

mpc

[jussi]

I found it very hard to get perfect fitting tenons from the tablesaw. If your off by only a few thou it's really hard to dial the blade height that amount. Also it's Way too easy to put too much or little pressure. So even if you get one that's perfect the subsequent ones might be a tad off. My answer. Hand tools. Much easier to dial in that last pass and take only a few thou off. My go to tool is a router plane. But you can also use some sort of rabbet or shoulder plane.

[TCAS]

Now the big problem, M&T joinery. I have done plenty of mortises, but am not sure I am doing my tenons "right"...

If you are comfortable cutting mortises then why not consider some loose tenon joinery? Once you have your set-up dialed in to cut the perfect tenon stock for your mortises you can cut as much as you ever think you will need. Sort of a "one and done" philosophy.

I figure if it's good enough for David Marks, it's good enough for me!

David J. Marks - Loose Tenon Joinery

[JimD]

I use a jig that slides on the rip fence and holds the piece vertically for tenons in short pieces of wood. For big pieces (say a bed frame) I like to use dado blades on my radial arm saw and trim with a shoulder plane (mine is a Stanley). Even for the short pieces, I use the shoulder plane when I need to take off a tiny amount or deal with small variations in thickness that turn into variations in the tenon. It's easier to plane when you use the dado blade, however.

At around $100 a shoulder plane always seemed like an extravagance but it does make tenons a lot easier.

Jim

[dbhost]

From what I am gathering here, there are a MESS of different methods, but they all seem to be along the same lines of sneaking up on the final size.

I should mention I typically thickness all related stock, to the same exact thickness, or at least as close as my planer will get me, at the same time prior to cutting to length, I typically have some surplus that I use as sacrificial test pieces, to make sure my setup for the tenons is either spot on (rare) or close enough, I have then followed up with a sanding block and some 100 grit to knock the final resistance off the tenon until it is a wiggle fit. Then I move on to cutting my actual to be used tenons, and so on, and so on etc...

from all that has been said so far, I don't think I am too far off, I was just double checking myself...

[capncarl]

Do you have to cut extra pieces for spares to replace the ones that the dogs chew up? Or is this dog trained?

[dbhost]

He is trained. About 4 years old. He knows not to chew on furniture, and we give him lots of chew toys to keep him busy...

[JimD]

If there will be lots of slats, you might want to consider something other than mortise and tenons on each end. It will be challenging to align everything at glueup. I've made a couple beds from plans in Woodsmith where you make the top rail out of two half thickness boards with dados in them that are a snug fit on the vertical pieces. Then you glue up these pieces to create a series of square holes you can slide the slats through. Their plans show these holes in the top and bottom rail but I put mortises on the bottom rail and slid the slats down to their mortise. It's a lot less tense to do these one-by-one after the basic structure is in the clamps as opposed to trying to align a dozen or more pieces before the clamps can be tightened. A cap piece covers the holes.