# Mortise & Tenon Jigs



## sreilly (May 22, 2018)

I have looked at a ton of plans to build one and the received an email that showed the Leigh Super FMT Frame Mortise & Tenon Jig on sale at $399 versus the regular $599 price. So is it worth it or can I build a suitable jig for a good deal less? At this point I don't see angled joints to be needed but you never know what future project will present. Another thought I had was I see tenons on long board such as bed rails and wonder how they get those long boards cut. I mean I've seen plans for mounting routers on their sides and can see how that works but what about the Leigh jig? Anyone with experience using one of these? The Pro model at just over $1K seems a bit too much but I haven't seen a way to compare the two. A call to Leigh may be needed soon.


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## DesertRatTom (Jul 3, 2012)

I think for someone doing a lot of M&T joints that a Leigh jig is a good idea, but for a moderate user, it's hard to beat a nice conventional mortising machine with the chisel and bit combined. The $400 price for the cheaper Leigh jig is what it lists for on Amazon. If you are more comfortable with routers, it seems to be a decent item. I'd have to be doing constant M&T joints to pop for $1K.

IMHO. I hardly ever use this joint, but might be more inclined if I had a mortising machine or jig. Since I have a nice rabbiting plane, I'd probably go with a conventional mortising machine and the table saw+plane for tenons.


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## Cherryville Chuck (Sep 28, 2010)

I made a screen door for my porch a year ago roughly (pics are in my uploads) and I put it all together with floating tenons. The mortises were made to each frame part with a home made jig and router. I think I used a guide bushing rather than a bearing guided bit as I recall using a 2 1/2" long straight bit which doesn't have one. The jig took maybe a half hour to make. It just has to register from one side of your material, either from the inside face or the outside face depending on your design and the top just has a slot in it. It's really not that complicated when you start breaking the problem down. If you look at their jig that's probably how it's built. It would likely have the advantage of changing the offset from the edge easily which my jig did not but mine was thrown together for that particular job I needed it for.

I also have a drill press type hollow chisel mortiser and I have a tenoning jig for my table saw which also get used. If you wanted to cut a tenon on something long which could not be stood up on a TS then the easiest method is to use a router and straight bit and take material off the sides as if you were doing a lap joint. Then you just work to a stop clamped on your work. The downside of this method is dialing in the correct thickness for the tenon. It's better to sneak up on a good fit by taking a couple of light passes after the majority of wood is hogged away but that doesn't leave anything for the router to sit on unless you build a "box" around the part you are tenoning with the same thickness as your work piece.


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## Stick486 (Jan 4, 2013)

sreilly said:


> I have looked at a ton of plans to build one and the received an email that showed the Leigh Super FMT Frame Mortise & Tenon Jig on sale at $399 versus the regular $599 price. So is it worth it or can I build a suitable jig for a good deal less? At this point I don't see angled joints to be needed but you never know what future project will present. Another thought I had was I see tenons on long board such as bed rails and wonder how they get those long boards cut. I mean I've seen plans for mounting routers on their sides and can see how that works but what about the Leigh jig? Anyone with experience using one of these? The Pro model at just over $1K seems a bit too much but I haven't seen a way to compare the two. A call to Leigh may be needed soon.


I have the FMT Pro...
the difference between the two is the body of the jig... formed steel vs machined aluminum..
there is nothing like them and no going back either..

the smart money on tenons on long boards is a router and a planer type bit ..


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## sreilly (May 22, 2018)

Thanks for the input guys. I did call Leigh and was told that the Super FMT Frame Mortise & Tenon Jig was being discontinued because the Pro was outselling it. He did mention that they are making a new beginner jig with more limited ability such as fewer thicknesses and no angles that will likely sell for $200. At the price point for the Pro version I begin to wonder if that wouldn't be better spent on a Festool Domino. I'm getting a headache.....


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## CharleyL (Feb 28, 2009)

I have an FMT Pro and have used it on long work two times. The first time I borrowed the top rail of my neighbor's deck rail and clamped the jig to it facing his back yard, so the long work could hang down past the deck. The second time I clamped it to my shop attic floor at the side edge of the pull down stairway. This time the jig faced me, but I had to stand sideways on the stairs while using it. Both ways worked well though. You just have to occasionally work "outside the box" and figure out alternate ways to do things. Both the FMT Pro and Super jigs work the same and seem to be just as accurate. The difference between them is the frame. The Pro jig is aluminum and the Super jig is stamped steel. I probably would have purchased the Super FMT if it had been available when I bought my FMT Pro jig.

Charley


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## sreilly (May 22, 2018)

Thanks Charley,

With that in mind then I guess they both use the same templates? With the Super being discontinued I was wondering if it would be difficult to get parts that wear. But if they use the same parts then I'd guess not. And I'm also guessing bits can be had by many vendors but maybe special bushings? Just trying to see what might be the problem down the road.

-Steve


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## Terry Q (Mar 2, 2017)

sreilly said:


> Thanks Charley,
> 
> With that in mind then I guess they both use the same templates? With the Super being discontinued I was wondering if it would be difficult to get parts that wear. But if they use the same parts then I'd guess not. And I'm also guessing bits can be had by many vendors but maybe special bushings? Just trying to see what might be the problem down the road.
> 
> -Steve




They use the same templates, router bits are common and it doesn’t use any bushings, the templates guide the bit. I would think $200 off the super fmt would be a good deal since they are discontinued.

The major differences, besides the steel base instead of aluminum base, is that the clamps aren’t as easy to use and the positioning curser for locating the mortise or tenon is less convenient.

For those unfamiliar with the Leigh FMT you may not understand the reasons for so many bits in the set that they sell. Not only can you make the common 1/4 or 3/8 or 1/2 sized mortise and tenons using those size bits (which most people would be happy with), but by using a combination of bits you can make just about any small size mortise and tenon joint for delicate pieces. They show an example of matching mortise and tenons cut into wooden match sticks.

A few months back someone was trying to make chopsticks with two different woods joined end to end to make a chopstick. Using the FMT would have allowed for a mortise and tenon fit where the end of one wood could have slid into the end of the other piece of wood, regardless of the size of his sticks.


In woodworking there is always more then one way to accomplish something.


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## CharleyL (Feb 28, 2009)

sreilly said:


> Thanks Charley,
> 
> With that in mind then I guess they both use the same templates? With the Super being discontinued I was wondering if it would be difficult to get parts that wear. But if they use the same parts then I'd guess not. And I'm also guessing bits can be had by many vendors but maybe special bushings? Just trying to see what might be the problem down the road.
> 
> -Steve


There isn't much to wear out. Yes, the templates are the same. Only a very smooth slightly tapered pin rubs on them and they are a hard plastic. The pin rotates via a knob on top and this lets you make very fine size adjustments of both the mortise and the tenon being cut, so you can get the perfect fit desired. I think this one inovation makes the FMT jigs superior to every other jig on the market

The bits used with either FMT jig are standard spiral up cut bits available from many sources. 

Bushings? There aren't any. The top guide plate that the router attaches to has two steel pins sticking out of the bottom of it. One steel pin in the right side slides back and forth in a close fitting plastic guide. The pin on the left is the tapered pin with the knob adjustment that I mentioned above. You follow the plastic template with this pin and the top plate moves the router, kind of like a pantograph does as the router cuts the mortise or the tenon. You follow the outside of the template when making the tenon, and the center slot of the same template when making the matching mortise. It's located on the front left of the top of the jig and not located anywhere near the router bit.

There is an alignment sight that slides into position with cross hairs that you use to position the work location for each mortise or tenon. When making more than one mortise or tenon, you only need to use this sight for the first piece setup. Then every identical piece can be cut without the sight. The design of the top plate prevents you from damaging this sight, so you have to move it back out of the way before you can rout. The top of the jig slides X and Y and has a position lock, so you can align the cross hairs to a mark on your first part. This sliding top plate also has adjustable stops, so you can set up to four locations when you want to make a group of up to four mortises and tenons. Once set on the first part, you just slide and lock this X-Y table from stop to stop and rout each mortise or tenon. You do both the mortises and the tenons with the same setup, so the fit together perfectly when completed. Again, no other M & T jig that I know of has this feature either.

The FMT jigs cut mortises and tenons so perfect and beautifully that it's a shame that they won't ever be seen after the project is glued together. I have make them in scrap pieces to show my clients what the inside of their joints look like. Otherwise they never have any appreciation for the quality.

Charley


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## sreilly (May 22, 2018)

I have to admit that I'm seriously looking at buying one of the Super models. At this point I can't see any disadvantage if I want clean and accurate mortises.

Thanks for all the feedback and detailed information. I love this group. I'm getting poorer but I love it.

Steve


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## Stick486 (Jan 4, 2013)

sreilly said:


> I have to admit that I'm seriously looking at buying one of the Super models. At this point I can't see any disadvantage if I want clean and accurate mortises.
> 
> Thanks for all the feedback and detailed information. I love this group. I'm getting poorer but I love it.
> 
> Steve


one of our strongest attributes is helping others spend their money...


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## sreilly (May 22, 2018)

Well it almost didn't happen. I checked Amazon and they were sold out, Woodcraft closest to me in Richmond an hour and 20 minutes didn't have any, yeah I called, so Roanoke (2.5 hours away) actually had one left and they were great to take my CC so my son could pick it up. I'll meet him tomorrow morning in Farmville while he's on a job. Talk about a last minute decision that almost didn't make any difference....but I now own one.....even if I haven't seen it yet.


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## Stick486 (Jan 4, 2013)

Sam has, er, had the Domino and used it at times at near production levels... 
every time he turned around there was another ''option/accessory'' to buy (there were a lot of them) running his cost into the thousands of dollars... 
everything for it was expensive propitiatory..
after his 2nd transmission failure, w/ Festool balking on the warranty the second time, he got rid of it...


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## Cherryville Chuck (Sep 28, 2010)

Stick486 said:


> Sam has, er, had the Domino and used it at times at near production levels...
> 
> after his 2nd transmission failure


That was something I was wondering about was how reliable that mechanism is that walks the bit around. Not that I was thinking about getting one anyway. The rule that the more complicated the mechanism is the more likely it is to fail always holds true.


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## CharleyL (Feb 28, 2009)

Steve,

When you use the FMT to make tenons, make a light climb cut pass all the way around the tenon first. This will give you a clean shoulder around the tenon, Then continue, but in the opposite direction to cut the tenon to it's proper size. If you will be making a tenon that's longer than 3/4", make it first at about 1/2 of the length and then repeat at the full depth setting. I learned to do this to keep the vacuum port from plugging. chips longer than about 3/4" will bridge across the vacuum port and plug it quickly. I attach a piece of clear Lexan to the front of my jig with some Velcro, not to look through, but to keep the tenon cutting chips from hitting me when I cut the front side of the tenon. It not only keeps the chips from hitting me, but also helps the vacuum port behind the tenon to pull some of the chips from cutting the front side of the tenon.


When making mortises, make repeated plunge cuts to full depth to clear out most of the wood. Then go back and forth at full depth to clear out the remaining material. Then continue at full depth following the sides of the template groove to cut the mortise to the proper width. Trying to just plunge and then cut sideways puts heavy load on the router and bit, and can produce a mortise that is not the correct dimension.

If you find that your mortise and tenon fit too tightly, back the adjustment knob on the tope of the tapered pin that follows the template about 1/8 of a turn and re-cut both the mortise and the tenon. Repeat this until they fit together perfectly, but realize that a few thousandths gap is necessary for the glue or you will be using a very big hammer at glue-up time. If the mortise and tenon fit too loose, reverse this process, but you will need to cut a new mortise and tenon this time.

Once the adjustments to your jig produce the perfect fit, you should be able to make as many mortise and tenon joints that you need and all will fit perfectly and even be interchangeable as long as you don't change to different material or a new router bit. If either has to change, you may need to make new test pieces and make small adjustments before continuing. 


Charley


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## sreilly (May 22, 2018)

Charley,

That's great advice from experience. Another shining example in the value of this group. Printed out and posted on the wall in the shop. I'm just into the beginning of the assembly. I have it mounted to a board, all parts identified and laid out. Just got to the part of attaching the plate to the router. Having to wait a few hours as the new router, Bosch 1617EVSPK, hasn't arrived just yet. Glad I saw an email with a special on them as I got the kit for $150 and this way it can stay mounted, the one in the router table stays mounted, and the Colt and 1617 is on the shelf. Looks like I'm starting a collection of routers. Several old Craftsman, a Montgomery Ward Power Kraft, and I can't find one other that I may have given to my son......

Charley again, got off topic, but thanks for the advice. It's good to get it in the right direction from the beginning. I'll also reread the manula while waiting. It's something I've learned from years of missteps and mistakes. 

-Steve


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## CharleyL (Feb 28, 2009)

Steve,

A bit more information about how I ended up with the FMT jig and some more tips.

You will need a router that can take both 1/4 and 1/2" bits but a huge and heavy router isn't a good choice. I usually use one of my DeWalt DW618 routers with my FMT jig. The router base of this router has matching holes for mounting it directly on the top plate of the FMT

When I first bought the jig I tried using a heavier router and I wore out my arm muscles lifting it on and off of the FMT. The 2 hp size routers work fine on an FMT jig with plenty of power for the job, yet are light enough to lift on and off of the jig frequently. 

I built a wood platform to hold the router that's the same height as the jig and place it behind and off to one side of the FMT so I can almost slide the router from it to the FMT and back. For me, this has proven to be very handy. Leigh says that the router does not need to be removed between cuts, and is only necessary when needed for alignment of the first piece to be cut, but I've found that I want to see better when removing and replacing each piece , so I frequently remove and replace the router when I'm using the FMT. 

I bought my FMT Pro jig when I was faced with a job that needed over 1,600 M&T joints and it paid for itself several times over on that one job. Before going to the FMT I had researched every way that I could find for cutting the joints faster and more accurately. No other M&T jig on the market had this fine adjustment capability, and no other jig that I tried made joints with the repeatable accuracy of the FMT. Back before purchasing the FMT I had first started making M&T joints the old way using mortising chisels, and my drill press using square mortising bits, then I bought a square chisel mortising machine when the drill press wasn't adequate, then built a router mortising jig from wood, and made floating tenon stock using my table saw and planer, and I then bought a Mortise Pal floating tenon jig. I was about to go with the Mortise Pal and floating tenons for this large job when I bought the Trend M&T jig. It worked and could do both the mortise and the tenon, but it wasn't nearly as repeatable nor did it have a fine adjustment capability So my M&T joints have evolved over many years learning curve before I finally bought the FMT.

Two years after buying the FMT, I sold the Trend jig for about 1/2 of what I paid for it. I had only used it for 2 days when I decided that it wasn't capable of doing what I needed as accurately and repeatably as I was expecting from it. The Mortise Pal has now been sold too, and I now do all of my mortise and tenon work, and even floating tenon work using my FMT jig. 

If you should ever decide to use floating tenons (they are sometimes a better choice for certain uses), cut the mortises in both pieces instead of just one using the FMT. Then cut long stock for the tenons the width and rough thickness that you will need using your table saw, and then plane them to the exact thickness needed with a planer. The edges of this tenon stock doesn't need to be rounded. Just make them the width of the flat sides of the mortise that they are being made for. Then cut them to length as they are needed, making them about 1/8" shorter than the total depth of the two mortises. The 1/2 round mortise hole left at each end of the mortise that the square ended tenon doesn't fill becomes a good place for the excess glue to go. The flat surface side areas of the tenon and mortise are where the joint strength is anyway, so these 1/2 round mortise end areas aren't needed for strength. You can round the edges of the tenon stock if you want to, but why do it if it isn't necessary. I've never had one fail when glued with Titebond II.

Charley


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## hawkeye10 (Jul 28, 2015)

I have never made a Mortise and Tenon joint but if I did this is how I would do it. Besides I like using my router table. It makes me feel all warm inside. :laugh2:


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## Cherryville Chuck (Sep 28, 2010)

I've never liked the idea of lowering something onto a spinning bit like that. I know lots of people have said they've done it for years with no issues but it only takes one issue to bend or break the bit or damage the router armature. The only way I would personally do that is if I had something to act as a second fence that left a gap just wide enough to slide the board into, effectively trapping it. 

My personal preference is to take a piece of ply with a slot in it for a guide bushing and rig it to sit on the edge of the board and use a hand held plunge router to make the mortise. I feel a lot safer doing it that way even if it takes longer.


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## Stick486 (Jan 4, 2013)

plan ''B''....

.


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## Cherryville Chuck (Sep 28, 2010)

The drill press one works well too. I have a Delta 16 1/2" and the Delta attachment. I think I paid $65 at a woodworking show about 20 years ago for it. The Powermatic is better but it's also $550. Also the mortiser or mortise attachment is only good for the sides of pieces. If you need to do the ends it's back to the router. For the sides the mortiser or mortise attachment is the way to go. Fast and the mortises are square so that you don't have to square the mortise by hand or round the tenon..


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## CharleyL (Feb 28, 2009)

If the three of you watched the FMT jig being used, or used it yourselves, you would be sold on it. Using it is just like plunging a spinning router bit into work from above. You have full control of the router and it's mounted on a plate that's held captive by pin guides in the bottom of it. Then the right hand guides the router while the laft hand holds a handle on the plate and steers the router to make the mortise or tenon by following the template with the pin in that end of the router plate. The top of the jig is wide and deep, so the router movement is fully balanced on the top of the jig during it's whole movement. The left pin follows the template and there is no guide bushing on the router. Stick's photo above is similar to the mortising machine that I once had before finding better ways to make mortises using a router. I'll never go back, unless for some reason the mortise ihas to be a square through mortise, but I would probably still use a router and then square the ends with a chisel. I sold the square chisel mortiser that I had years ago, but still have the chisels and drill press adapter.

Charley.


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## Stick486 (Jan 4, 2013)

CharleyL said:


> *If the three of you watched the FMT jig being used, or used it yourselves, you would be sold on it.* Using it is just like plunging a spinning router bit into work from above. You have full control of the router and it's mounted on a plate that's held captive by pin guides in the bottom of it. Then the right hand guides the router while the left hand holds a handle on the plate and steers the router to make the mortise or tenon by following the template with the pin in that end of the router plate. The top of the jig is wide and deep, so the router movement is fully balanced on the top of the jig during it's whole movement. The left pin follows the template and there is no guide bushing on the router. Stick's photo above is similar to the mortising machine that I once had before finding better ways to make mortises using a router. I'll never go back, unless for some reason the mortise has to be a square through mortise, but I would probably still use a router and then square the ends with a chisel. I sold the square chisel mortiser that I had years ago, but still have the chisels and drill press adapter.
> 
> Charley.


I hope I'm not part of the three of you group...
both units have their place...
the PM unit shines in large productions, compound joints and tusk tenons....


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## sreilly (May 22, 2018)

hawkeye10 said:


> I have never made a Mortise and Tenon joint but if I did this is how I would do it. Besides I like using my router table. It makes me feel all warm inside. :laugh2:
> 
> https://www.youtube.com/watch?v=dzjWfHJm5kc&t=10s


Looks good but if you're doing a mess of them the jig makes fastre work of it with highly repeatable accuracy. I could see with a good deal of practice you might get very good at this. Things that become more variable is like the start point, especially multiple times to get the full depth. Lining that up each and every time looks more like a gamble but maybe not. I haven't tried. But then again I have the jig now and as soon as I finish putting it together I'll try it out and report back. With Charley's excellent advice I should be able to get this done without too much issue. Just need to get time to assemble and test. Yes, it was a long day yesterday and when the new router finally was delivered yesterday I was pooped out. I'd forgotten there were early 5 o'clocks.....And today was a honey do day of going into town and taking care of the things life demands like getting food, seeing the doctor, taking the better half to brunch.....the things that keep me on the better side.


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## bfblack (May 2, 2012)

I use floating tenons for all my mortise/tenon work. The mortise jig is shop built and is based on what I learned in a Router Joinery class at Santa Fe Community College. The attached photos show front and back of mortise jig plus the jig being used to make a mortise in a table leg. I used a DW621 plunge router because of the good dust collection capability in conjunction with guide bushings. Notice that I placed notes on the bottom side of the jig so I know its intended purpose. My most recent project contained 54 mortises and I am pleased with how the process works.


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## CharleyL (Feb 28, 2009)

Ben,

I've made jigs like yours prior to buying the Mortise Pal, and they do work, but different sizes are needed for each width mortise or some stops needed to be added to one long slot when making a jig that will do multiple lengths of mortises, or many different ones of the jig need to be made and then stored between uses. When I bought my I-Box jig and discovered all that it could do, the dozen or so different shop made box joint jigs all went to the burn pile and now I have only the I-Box jig. I really don't like storing multiple sizes of jigs. My shop made jigs are stored from hooks in my shop ceiling, and I'm running out of ceiling space.

A suggestion for holding up your vacuum hose when routing and sanding - I hold up the loop in my vacuum hose using a retractable clothes line unit that's attached above my work bench. The plastic fitting on the end of the clothes line gets attached to the vacuum line with one of the Velcro straps that were made for securing power cords. I acutally use several of these to secure the power cord and the vacuum line bundled together and then one to attach the clothes line to the middle of the loop. If I remember correctly, I had to add one additional turn to the clothes line spring for it to pull hard enough to lift both the vacuum hose and the power cord so it stayed above the work bench.

Here is the one that I have, 

https://www.walmart.com/ip/Woolite-...75035&wl11=online&wl12=51882302&wl13=&veh=sem

Charley


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## harrysin (Jan 15, 2007)

I stopped making conventional mortise and tenon joints years ago when I saw loose tenons. Over the years I've used all sorts of methods to make these joints but a while back I made this simple mortise jig and the loose tenons are made on the router table.


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## sreilly (May 22, 2018)

Well I finally got time to put the jig together and read, then re-read the manual. I did my first mortise and tenon yesterday afternoon. As with any tool it takes some practice but was very pleased with the outcome. My tenon was accurate, smooth, and extremely uniform. For the mortise I made a full depth plunge at both ends and then took 3-4 passes to work down to the bottom. The bit that comes with the jig is a 5/16" spiral upcut HSS bit and it shaved the tenon like butter but then I was also using scrap yellow poplar. It made a good clean cut but I noticed I was leaving burn marks at the inside of the ends. I also noticed the first mortise was "loose" in that I could slide it maybe 1/8" or less so reading in the manual I made adjustments to the left guide pin. I hadn't seen before where the pin is tapered and the guide is as well so making height adjustments on this guide gives extremely fine tuning to the length of the mortise. Where I think the manual could be better is by having you set the pin at the deepest point which will give you a shorter length and then adjust creeping up on the exact fit. Instead they suggest setting the initial at 2.5 full rotations from the bottom. But for me that made it too long so you waste that cut, make an adjustment, and try again. After 4 tries I had it fairly well dialed in. What I'm not sure about is just how tight the joint should be. I know it shouldn't require a hammer or extreme muscles to put together but it needs to be loose enough so any glue used in the joint doesn't squeeze out when joined. I'm also guessing that spreading glue inside the mortise and lightly on the tenon will assist with assembly but I'm likely to lose most of the glue on the tenon when inserted?

Initial impressions is this jig covers a good many size joints with the included guides and the one bit. The cuts are clean and you have infinite control to make minute adjustments as needed. I agree that having one jig to make many varying sized joints is a plus not to mention multiple joints. I have a large pile of scrap that will be turned into fancy kindling very soon. My neighbor will be very happy. 

I have ordered the dust collection box as this jig puts out a ton of sawdust and from what I can see the attachment should make it much cleaner to use. I will use my old Craftsman shop vac instead of the CV1800 for this. I also noticed a great deal of extremely fine sawdust so running the ceiling mounted air cleaner is a must along with a mask. The table saw 4' away had a very fine coat of saw dust on first cut. The router I'm using for this is a Bosch 1617EVSPK plunge and it will stay attached to the jig router plate. I used the highest speed setting to make the cuts. This jig has opened a new selection of joints I had not previously used. I'm like a kid at Christmas thinking of all the ways I could have used this long ago.

I've posted a few pictures to show what I may not have expressed well.


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## Stick486 (Jan 4, 2013)

nice....
way nice...


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## sreilly (May 22, 2018)

So the education continues as do the questions. The upcut spiral bits are listed with shank diameter, cutting diameter, overall length, and depth of cut. Obviously a 1/8" cutting diameter on a 1/4" shank is only going to be able to cut as deep as the specified depth of cut where say a 1/2" cutting diameter bit on a 1/2" diameter shaft should be able to cut as deep as the overall bit depth less the amount taken for the collet and the space between the router base and wood. I think this makes sense. So one needs to determine fairly early on what size tenon depth is needed. The case I'm thinking about is say doing a through mortise and tenon on a 3-4" thick workbench top. Assuming you can get a bit long enough you could do the top side, flip and do the bottom making the needed depth 1/2 the thickness of the top. But then you run into the limitation of cutting the tenon as you can only cut as deep as the depth of cut for the bit. Looking at Whiteside, the deepest upcut spiral bit they have is a 1/2" shank with a 1/2" diameter cutter with a depth of cut of 2-1/8" leaving it at least 7/8" short however I guess this may work for a non-through T&M joint. I guess I really need to look deeper at the math behind these joints and what is accepted procedure. For the through I guess you'd fall back to the old tried and true hammer and chisel routine and make them square and use the table saw to make the square edged tenons. I think I need to find a good source for this joint to study and see what needs to be considered when designing projects with this joint. Of course most furniture using the through M&T won't be near this thick so it's a none issue but there are always exceptions......


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## Stick486 (Jan 4, 2013)

a through M&T is a tusk tenon...
when you get to capacities/limit of your tools it's time to rethink the process...
a bench or a *box mortiser *is the ticket for this (on thick(er) materials) because you are entering into timber construction...
for thicker materials, still using your Leigh, go w/ a floating tenon..
or cut the fixed tenon to length as a shouldered tenon on the TS using a dado blade
w/ careful layout, turning your piece over works on the Leigh for the mortises...


*NOTES:*
hogging out mortises (and some tenons) is a plus for you and your operation as you are only ''cleaning'' up...... 
never use a spade bit for hogging... the bit's guide point sets up a fault line(s) in the material's grain leading to cracks/splits as the material moves/dries......
if you hog 1st and then use a long straight or helix bit will work well... 
1/2" Double Flute Straight Bit
remove the bearing..
3/4" Downshear Helix Flush Trim Bit

.


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## bfblack (May 2, 2012)

Charley, thanks for your comments. Relative to the Mortise Pal, it looks like a well made jig. Unfortunately, they are no longer in business. Sometimes it is difficult to take a good idea and turn it into a profitable product. From their literature, I noticed the limitations you mentioned on the Mortise Pal. I will check out the clothes line gadget you mentioned. My shop ceiling is 13 ft high which makes it a pain to attach anything to it unless you have a 10 ft step ladder.


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