"My" Mortise and Tenon method

[Lincoln Myers]

I am building a bunk bed for my two boys. It requires 16 mortise and tenon joints.

I attended "The Woodworking Shows" (http://www.thewoodworkingshows.com/) a few years back and saw a demo by Marc Adams on how to make a self centering jig for a plunge router for making mortises. His thought was, it is easier to round the tenon, than to square the mortise. I have used this method a couple times and I like it, it seems to make sense to me. I have tried squaring the mortise on a couple projects and prefer rounding the tenon.

I round the tenon with a Nicholson #49 rasp that I bought from Boggs Tool (http://www.boggstool.com/index.htm) that I was referred to from either this site, or Badger Pond. They have a sharpening service that I haven't used, but have heard good things about.

I cut "the long sides" of the tenons on my table saw (Jet Contractor) w/ a 1/2 inch dado, then cut "the short sides" with a Japanese pull saw (Marples from Home Depot, ~$17.00 which worked quite well).

I didn't cut all sides on my table saw with the dado, b/c there is something amiss on my alignment on the saw and don't have time right now to troubleshoot it. Besides cutting the tenon partly by had was fun.

http://www.lincmyers.com/images/Mortise.jpg


http://www.lincmyers.com/images/Tenon.jpg

-Linc

[Dan Forman]

So what does the jig look like?

Dan

[Lincoln Myers]

So what does the jig look like?

Dan

I will post a picture of it when I get home later tonight. :)

-Linc

[Frank Pellow]

Lincoln, that sounds like a good idea to me. It's one of those ideas that is obvious once someone else thinks of it. I will try it the next time I need such a joint.

[Dave Richards]

Looking forward to seeing your jig but I wanted to say, I like the warm tungsten cast in your images. Very nice for wood. ;)

[Lincoln Myers]

...Thanks Frank, Dave...

Below are the pics of the Jig.

It is made from lexan 3/8" thick? All the holes for the sub-base are transferred from the existing router base plate directly to the protective plastic coating on the lexan (polycarbonate) before it is removed. Holes are then drilled out and the shape is cut to match the router base. I bought all the stock for this jig from eBay pretty cheap.

The 2 holes that hold the black pegs (1/2" plastic dowel stock) are 1/2" holes with the pegs just friction fit inside. A little sanding was required on the pegs to create a slight taper to get them started, then just a tap or two with a hammer and they're good to go.

The original holes I made in the jig were not quite wide enough apart for my current project, so I drilled two additional holes equa-distant from the existing holes. This modification was not quite as exact as the original holes, b/c it was difficult to get the exact center of the existing holes to measure from, so it may make sense to drill 2 or 3 sets of holes originally before removing the protective coating from the polycarbonate.

To use the jig simply place it over the workpiece and rotate it until the pegs snug up against each side, this perfectly centers the bit over the workpiece. There is no need to mark the long sides of the mortise, just the end/stopping points to define its' length. I just sneak up on the lines, but stops can also be clamped to the workpiece for this purpose.

I think that covers it. It is really quite slick. I'm not sure if Marc Adams invented this, or was just passing it on from someone he learned it from. He is really a good teacher and is very interested in helping others learn techniques and enjoy the hobby.

-Linc


http://www.lincmyers.com/images/Jig01.jpg

http://www.lincmyers.com/images/Jig02.jpg

http://www.lincmyers.com/images/Jig04.jpg

[Dave Richards]

Lincoln, that's a great application of an old, old concept. Thanks for sharing. I was expecting something much more complex. :o Looks like it does an excellent job.

[tod evans]

lincoln, nice jig! i`m a firm beliver in the ol` k.i.s.s. addage.....02 tod

[Dan Forman]

Lincoln---Thanks for posting the jig pics. I should have said something about those nice mortices too, but sometimes around 2AM all that comes out is the short version. :D

Dan

[Stu Ablett in Tokyo Japan]

Very cool!

I wonder, if you put a fatter peg on one side, would you then have an off-ste tenon?

Sometimes you do not want the tenon right smack dab in the middle of the board.

Just thinking out loud here.

Cheers!

[Norman Hitt]

Very cool!

I wonder, if you put a fatter peg on one side, would you then have an off-ste tenon?

Sometimes you do not want the tenon right smack dab in the middle of the board.

Just thinking out loud here.

Cheers!

That would probably work OK, Stu, but it seems to me, that it would be simpler to just cut a thin shim, (the thickness you want the offset to be), and lay it in the stack he shows, along one side of the piece you want the mortice in, and that would give you the offset. This way, you wouldn't have to worry about modifying the jig, but could make any series of offsets by just using the appropriate thickness shim.

[Stu Ablett in Tokyo Japan]

That would probably work OK, Stu, but it seems to me, that it would be simpler to just cut a thin shim, (the thickness you want the offset to be), and lay it in the stack he shows, along one side of the piece you want the mortice in, and that would give you the offset. This way, you wouldn't have to worry about modifying the jig, but could make any series of offsets by just using the appropriate thickness shim.

Yep, for sure that shim would work too, an it is simple, materials are easy to get as well.

The thing is, I know that I would forget the shim half the time, then again, if I put the fat pin on the wrong side I'd also have a problem......

Yep, for sure there are ways I could screw this up :o

Cheers!:D

[Jerry Olexa]

Thanks for sharing your idea and pics. I'm still amazed there are so many diff ways to do M/T. I just bought a dedicated mortiser which I'm anxious to try on a real project. In past I've used router and TS plus chisel.

[Alex Berkovsky]

I have Marc Adams' Joinery DVD where he shows how to make it. I bought the material for it, but never got around to making it. Instead, I decided to make this mortising jig (http://i73.photobucket.com/albums/i232/jarhead8286/Woodworking/MortisingJig.jpg). Eventually, I will also make it for quick, centered mortises.

[Art King]

36395

36396

First an introduction: I am a hobbiest woodworker who reads the postings here at The Sawmill Creek with a great deal of interest. There is a great deal of sharing here and I enjoy the learning and comeraderie displayed here.
Below with any luck are a couple of pictures of how I do my mortices. These templates are made individually for each size and simply clamped to the work and cut with a plunge router using an upcut bit. It takes only a few minutes to make a template and routing time is quicker still. with it being this easy there must be something wrong with it?
The template shown is for an offset mortice.
Thanks for a really great forum
Regards,
Art King