How to create perfect mortice and tenon joints on a PantoRouter



For this little demo I ripped up some stock in Oregon that is about 35 by 75 millimetres: now those measurements matter a little bit in knowing the rest of this set up but regardless of what your measurements are on your stock, all of this will really still apply.

The first thing you're going to want to do is choose the template that's appropriate for the tenon that you're trying to create. Now just remember that the template size is going to be twice the size of the tenon, so there are a variety of templates of different sizes which lets you choose the one that's most appropriate. Like I said, my piece of stock is 75 mil wide so I want to make sure I get a tenon that fits comfortably within that.

How to measure the width of the tenon template

What I'm looking at here is the length of the tenon…alright I guess it's the width of the tenon more than the length, and I'm gonna measure tha st on these particular templates. Now they have numbers written on them in imperial but as far as I'm concerned that's not a real measurement system and you guys shall figure it out real soon so the middle one the B is about 60 millimeters long which is going to give me a 30 mil wide tenon, the large one is about 85 millimeters long which is going to give me a 42.5 millimeter long tenon, again because it's half, you get what I mean with the rest of these.

Now the middle size, the C, which will give me the 45 mil long tenon is the one that I've chosen that will give me, on a 75 mil piece, ample room on either side so I'm not weakening the join too much.

Setting your tenon templates

Once you've chosen your template you can slide the template onto the template holder and it's really important that the easiest way to do that is use one of the shafts of the bearings, place it through that center hole until it lines up with the hole in the template holder and then tighten up those little set screws. This makes sure that your joinery lines up with what is on the table.

So I have my centreline marked on the table and that is referencing this center point up here, once those screws are done up you can take this out and you'll use that later. The next thing you want to do is make sure that this template holder is set at the correct height. Now to do this you need to have already gone through the setup process which is involved with building your PantoRouter and that places this little stop so that your router bit is referencing the actual height of your bench here, so this assumes that you've already done that. Once that is set you actually only do that once, you should never really have to come back to that but assuming that is in the correct place.

Setting your template holder to the correct height

You get your piece of stock, which in my case again is about 35 mil, you place it on that little aluminium stop, you drop the template hole down onto it and you can lock that position off and then you can remove that stock.

The reason this works is because anything that's happening up here is happening at twice the distance then the router bit will move down here, so in order to get the router bit into the center position we want to raise this by twice that amount which is the full width of our stock.

Now this system kind of applies to most joinery that you do on the PantoRouter, but it's just a really nifty way to set that height without actually having to measure and then reference back to a ruler or anything like that.

Setting the router table fence for the PantoRouter

So we've got our template centered in the centre, we've got our template holder set to the correct height, the next thing you're going to want to do is set the fence, which is sliding around on your table here. Now this is one process where you do need to know the width of the material that you're working with. In my case like I said it's about 75 mil.

I've actually used a marking gauge to mark a little notch in the centre of that, that can help me but there are other ways to do this as well so like I said I've got the centre already marked on my table that's important for all joinery on the PantoRouter, I can line up that little center mark that I've done with my mark, engage on that center line and slide the fence up until they line up and lock it off.

The other way that you can do it is if you know this width which I do you can actually find that number on the scale here and you can line it up that way as well, the scale actually has a standard ruler and then essentially a half sized ruler or a double size ruler where one centimeter on the ruler actually represents two centimeters on the timber.

What that means is instead of having to do the maths of 75 divided by 2 and then finding that on the ruler you actually just find 75 on the ruler itself because it's at half width and that also is another way to line that up.

So now that I've set the fence, I'm actually ready to do my first cut which is going to be my mortise. Now I want my mortise on the edge of the timber here so I'm actually going to place this on the edge of the table, I'm going to use these little red stops here to line that up as well as the fence and then I can clamp that in place now to get some extra clamping pressure.

I like to use a spare piece of stock which is the same thickness and then use a bridging piece and actually clamp onto that because these clamps can only work in one orientation which means I can't turn it 90 degrees to put clamping pressure exactly where I need to, so this is a really nifty trick to making sure that it's all firm once it is firm you can move these little red paddles out of the way they're no longer applicable and we're ready to do that first mortise cut.

Cutting a mortice and a tenon on the PantoRouter

So a mortise is cut, looks nice and neat, I can now take that off and cut the tenon. So this piece is going to be my tenon piece and the tenons going to be on the end, so we're still using the fence for alignment but instead of lining up with the edge of the table here we're actually pushing this piece of timber past the edge of the table so that when this router bit has made its full depth of cut which is what I did, say about 33 mil, it's not going to contact this aluminium table.

So this is set up about, you know, 45 mil in front of the table and we can clamp that down to make sure that the depth is set correctly. We're actually going to bring the bit up to the timber like we did last time and then we're going to reset that depth stop down the bottom because we've actually moved the reference point that our timber is referencing off the bit.

Setting the depth stop for the perfect mortice

So I want this tenon to be 30 mil long, so I'm going to set it at 30 on that depth stop and that'll make sure it's at the right length. In order to cut the tenon we need to change the location of the bearing because we no longer want it running on the inside of this track here, so we can move it to the outside, however we also need to change the diameter of the bearing. Now this relates to the size of the tenon we want to create and the size of the router bit that we're using for this half inch bit or 12.5 mil.

We're going to use the largest bearing which is around 22 mil and that makes sure that our tenon is going to fit perfectly into our mortise that we just cut which is here now. As I was mentioning earlier the templates don't have square walls, they have tapered walls. What that means is we can do the same thing that we did when we're inside the slot, we can move the bearing back and forth to get a slightly tighter or a slightly looser tenon or looser fit - basically if you are right at the back of this template the tenon that we're cutting will be a little bit oversized and it probably won't fit but again it's a good place to start.

When you move it to the center it'll probably be pretty good and if you move it right to the front you might find that it's a little bit too loose, so again once you get the feel of the machine, and the bit that you're using, and the timber that you're using, and you'll have a much clearer idea of where is most appropriate for that particular join.

Making test joins

I would do a test join to make sure that I'd figured out where they need to be and that way I could run through all of them without having to test and go back and readjust but if you start off with the tenon being a little bit oversized you cut it you can test it and then you can bring the bearing down and make it a little bit smaller and test it without having to redo every join from scratch.

You can actually creep up on them which is really nifty. I'm gonna start in the middle because I've done this before and I know that that's gonna work. At least it's a good place to start.

Climb cutting on your router

I've got my depth stopped, this cutting procedure you're actually going to be climb cutting which is unlike almost any other routing application so you'll be running the router bit in the direction that it wants to go over the timber. Don't try and sink the router bit right into the meat of the timber and do a full pass, I like to do lots of shallow passes on the top and then a few shallow passes on the bottom until I've got most of that meat and then that's when you start running around the actual template.

Once you've removed all that material you can choose to either do it in a few passes in multiple depths, or you can just do it gently creeping up on it from both sides. Either way it’ll work. You're just not going to try and force the bit through a whole chunk of timber because that can introduce potential inaccuracies by just forcing the machine to work harder than it really needs to.

The PantoRouter’s Dust Collection

So, I'm ready to start cutting. One of the things I really like about this machine is that its dust collection is actually really effective. Yes, I'm covered in sawdust right now because we've taken the shroud off so that we can film it but it's really easy to take on and off, which is nice because it means for setup if you need to see the bit or when you're changing the bits, it comes on and off really easily by just clipping onto this plastic shroud there and clipping off again.

It forms a very effective funnel for a standard vacuum cleaner to take all that with dust away. So I cut the tenon, I measured it with calipers and it was about 13 point something millimeters, so it was going to be a bit too tight, so then I move that bearing down the template like I mentioned and then ran it again which just shaved off a fraction and now it's perfect.

A seamless, perfectly fitting mortice and tenon joint

It's exactly, exactly twelve point four so slides in there beautifully, that joint is just seamless and it is firm but I didn't have to whack it in with a hammer and it's a real suction fit, so you know really nice and tight again. If you are doing through tenons, it's worth doing a test to make sure that you can get absolutely zero space on the end of the tenon where it meets the mortise, but because this one's concealed you wouldn't really have to worry about that too much.

That portion of the join doesn't add a lot of strength because it's on the internal end grain anyway. If you needed to make sure that it was absolutely in the center you could run a test mortise on the end of the same piece of stock or a test piece that was the same width and then measure with calipers - the distance of the thickness of that wall there and the thickness of this wall there and adjust the fence accordingly.

That's a good way to make sure that you're really working exactly to the accuracy parameters of the machine and how it's all set up, if you didn't want this mortise to be right on the end here all you need to do is mark where you want it from the center so mark a centerline and then that will be the center of that mortise.

So if you wanted it directly in the center, you could do that too, that's the extent of this process. We've got way more videos that we're making on the process, so you can check them out on our YouTube channel.