# Compound tenon (2 angles)...how would you make this?



## Mcpowell (Dec 19, 2015)

There are 2 tenons on the above part. One is no problem as it has only one 5º angle. I can make that tenon on my tenon jig for my table saw or with my router on my Leigh tenon jig. However, the other tenon has a 5º angle in two directions. This tenon is my problem child. This tenon is illustrated best on the bottom left view of the attached drawing.

The only way I can think to make the double angled tenon is to use my router. I would make a oval patterned jig that would produce the 2" x .499" tenon. Then I could make a wedge which has a 5º angle in two directions. I could then clamp the work piece to the wedge and both the wedge and the work piece would be clamped vertically under the jig.

I think this would work, but I haven't tried it yet. Before I take the time to make the jig, I thought I would run it past the fine folks here.

Any suggestions?


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## bandit571 (Jan 20, 2011)

Bandsaw to cut, chisel to fine tune…


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## bonesbr549 (Jan 1, 2010)

mark it with an angle gauge and cut it with a good saw or bandsaw.


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## Loren (May 30, 2008)

I'd cut a "birdsmouth" on the table saw in two
cuts with the blade angled 5".


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## Mcpowell (Dec 19, 2015)

I hadn't thought about using my bandsaw. That's a bit scary to me as the shoulders may not be as precise as I'd like. This would require some practice before I'd be willing to test on a "real" piece.

The illustrated part is the side of the chair, so it will be very visible. I've got until the weekend before I need to tackle this portion.

Thanks for the ideas so far.


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## Loren (May 30, 2008)

Cut the shoulders by hand when band sawing.
The band saw does a good job on tenon cheeks
though. Your table may need to tilt both ways
or something like that to do both sides. Again,
a birdsmouth cradle can help by angling the
work piece instead of the table. The advantage
over fussing with an angled wedge is the
birdsmouth has the wedge integrated.

I was thinking of using the birdsmouth on the
Leigh jig to get the twist and using the jig's
angled table to get the angle. This will make
a nice shoulder as I'm sure you know, but
it's not that difficult to cut and trim a few 
shoulders by hand. If you're doing a lot of
them figuring out a machine approach makes
sense.


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## bandit571 (Jan 20, 2011)

Make the shoulder cuts first, then the angled cheek cuts. then cut for the width of the tenon…then the kerf cuts for the wedges..

One step at a time…


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## bondogaposis (Dec 18, 2011)

This where hand tools really shine. If you can draw the lines on a board you can cut them.


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## Loren (May 30, 2008)

You could also rip the stock oversized with a 
5 degree angle on one edge. Freehand
the cheek cuts on the band saw and cut the
shoulders by hand. Rip the 5 degree edge
off and then cut the other tenon.


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## RichT (Oct 14, 2016)

Why not make a 5º wedge to place between the part and the back plate on your Leigh jig? You will have to eyeball the target alignment (unless you scribe the target on the piece at 5º), but on something that small it'd be easy.


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## Mcpowell (Dec 19, 2015)

> Why not make a 5º wedge to place between the part and the back plate on your Leigh jig? You will have to eyeball the target alignment (unless you scribe the target on the piece at 5º), but on something that small it d be easy.
> 
> - Rich


Rich,
This is exactly my original plan. I figured I would use one 5º wedge for the "simple" tenon and another wedge, which would have two 5º angles for the compound tenon.

My Leigh jig is not designed for this type of tenon, but I think I can do a bit of adaptive engineering and make it work.

Regards,
Mark


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## RichT (Oct 14, 2016)

> My Leigh jig is not designed for this type of tenon, but I think I can do a bit of adaptive engineering and make it work.
> 
> Regards,
> Mark
> ...


I think you can too, Mark. There's nothing unusual about the tenon other than its orientation to the rest of the piece. Of course you'll have to miter the end so it's flush to the base plate, but from there, whatever angles the piece is mounted in the jig at should result in a tenon at the correct angles and with shoulders parallel to the top face (end) of the tenon. From what I see in your drawing (an excellent one by the way), that's what the goal is.


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## enazle (May 18, 2018)

1. How many parts and are they paired?

Back in the day when I was a pattern maker for a furniture factory, we had these Zuckerman contour machines to make parts like you have shown. However if they only needed a couple pairs to finish a order, I would mill them out by hand. If these tenons aren't exposed I would make the part to dimension and drill a couple 1/2 dowel holes then fill the space between with a plug that fit between the two dowels. if the rails aren't tenoned then the plug is not necessary.

Good luck


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## Mcpowell (Dec 19, 2015)

> I think you can too, Mark. There s nothing unusual about the tenon other than its orientation to the rest of the piece. Of course you ll have to miter the end so it s flush to the base plate, but from there, whatever angles the piece is mounted in the jig at should result in a tenon at the correct angles and with shoulders parallel to the top face (end) of the tenon. From what I see in your drawing (an excellent one by the way), that s what the goal is.
> 
> - Rich


Thanks Rich. I have access to a 3D drawing program with work. I know just enough about it to be dangerous.


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## Mcpowell (Dec 19, 2015)

> 1. How many parts and are they paired?
> 
> Back in the day when I was a pattern maker for a furniture factory, we had these Zuckerman contour machines to make parts like you have shown. However if they only needed a couple pairs to finish a order, I would mill them out by hand. If these tenons aren t exposed I would make the part to dimension and drill a couple 1/2 dowel holes then fill the space between with a plug that fit between the two dowels. if the rails aren t tenoned then the plug is not necessary.
> 
> ...


enazle,
I am making 8 chairs; so I have 8 lefts and 8 rights (16 total) to make. It's more than I want to tackle by hand, but not enough to go buy a true tenon jig. The tenon's are not exposed once assembled.


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## ColonelTravis (Mar 19, 2013)

Oops, at first I didn't see where you had to make a lot. I had said use hand tools, but that's a lot of chairs. Since I'm a hand tool guy I have no good suggestion but wish you luck.


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## bandit571 (Jan 20, 2011)

Make a few "stops" for the bandsaw, one for each type of cut….they would set the angle of the cut, and the depth of each cut. Make sure the table is square to the blade….

Maybe tomorrow,,,,I can give this a try on my bandsaw….and take a few pictures…


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## enazle (May 18, 2018)

> 1. How many parts and are they paired?
> 
> Back in the day when I was a pattern maker for a furniture factory, we had these Zuckerman contour machines to make parts like you have shown. However if they only needed a couple pairs to finish a order, I would mill them out by hand. If these tenons aren t exposed I would make the part to dimension and drill a couple 1/2 dowel holes then fill the space between with a plug that fit between the two dowels. if the rails aren t tenoned then the plug is not necessary.
> 
> ...


It looks like you have enough bulk to bore for 1/2" dowels. Buy 8 ea Drill Bushings 1/2" ID x 3/4" OD x 3/4" L off Ebay for $60 and make a jig for each side. It's tempting to make a jig out of MDF, but take my advice, use lumber if these jigs may be used again some day. I've had the mdf blow out when I tried to remove the bushing before. Popular or maple seem to work best.


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## RichT (Oct 14, 2016)

> It looks like you have enough bulk to bore for 1/2" dowels…
> 
> - enazle


Great. Another newcomer with no projects who's an expert on everything. Welcome to LJ.


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## Loren (May 30, 2008)

Chair stresses can be pretty intense with the 
small footprint of compact dining chairs. I
like dowel joinery a lot but for fine chairs 
I'd avoid it in favor of mortise and tenon. 
This is one of the rare cases, imo, where 
the M&T joint may be significantly more
durable. Most of the time in casework and
such it is overkill and well done dowels 
would suffice imo. Chippendale chairs run
the seat rail tenons all the way through the
back legs. Even though people weren't
supposed to lean back on chair backs in 
those days (they may have anyway if the
structure of their clothing and decorum 
allowed it) the back was there for other
reasons as well. I think we use them a lot
harder these days than Chippendale intended
but his joint choice has held up.

For bottom stretchers doweling them tends
to entail rather wider stretchers though I 
suppose dowels may be strong enough if
the seat rails and joinery are robust.


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## enazle (May 18, 2018)

> It looks like you have enough bulk to bore for 1/2" dowels…
> 
> - enazle
> 
> ...


There are Trolls everywhere aren't there? I guess you didn't see where I mentioned I was a pattern maker for a furniture plant. FYI, I also was a Architectural woodworker for 15 years and estimator for another 5 years for a prefinished, premium grade architectural woodwork manufacturing and installation company. The largest contract I ever estimated and won, was a $2,700,000 state capital building. My average job was around $200,000. So I guess I can say I have seen a lot of really nice woodwork.

Just because I haven't posted any projects doesn't mean squat.


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## RichT (Oct 14, 2016)

> There are Trolls everywhere aren t there? I guess you didn t see where I mentioned I was a pattern maker for a furniture plant. FYI…
> 
> Just because I haven t posted any projects doesn t mean squat.
> 
> - enazle


Sure, and I'm a billionaire mogul who taught Sam Maloof to make chairs.

Being a self-proclaimed expert with no credentials raises a red flag for many of us here, not just me. Post some projects and share some of your unique knowledge in a few blog posts. Show us what you've got.


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## bandit571 (Jan 20, 2011)

And there is always a self-appointed Forum Police to set everyone straight…and usually ruin a good thread…


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## bandit571 (Jan 20, 2011)

Table aprons, two longs, two shorts…shoulder cuts on a mitre box saw, cheek cuts on the bandsaw…


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## RichT (Oct 14, 2016)

> And there is always a self-appointed Forum Police to set everyone straight…and usually ruin a good thread…
> 
> - bandit571


Bless your heart.


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## Mcpowell (Dec 19, 2015)

I drew a jig (see below) that should make my tenon shape for me, and hope to pick it up today at lunch. I have access to a fiber optic laser at work, so I'm hoping "the guys" come through for me. It's made from .250" thick steel plate.

Once I have the plate, I'm pretty sure all I need is to make the correct wedges (precisely) and then locate the work piece correctly under my jig. So my weekend project is to complete the 2-angled tenon. I'll do it first and leave my stock long in case I mess up; then I can just cut it off and start again. I plan to practice a bunch before I move to my walnut stock.

Thanks for the ideas.

I'll take some pictures along the way and try to post them soon.


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## PPK (Mar 8, 2016)

I had the same issue to work with when I built some dining room chairs. Here's how I solved it: (I'm sure there are many ways to skin the cat, however)

http://lumberjocks.com/PPK/blog/88538 (scroll down about 2/3 of the way to find it.)

I've also attached a couple snap shots.


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## enazle (May 18, 2018)

What collar and bit diameter size are you planning on using. A 5/8" collar and 1/2" bit will leave a 1/2" tenon based on your drawing, but the length is going to be 2.025" long?


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## RichT (Oct 14, 2016)

The extra 25 thousandths will be on the tenon width as well. Both dimensions for the opening in the jig are 1.15" larger than the tenon.

Seems like a smart move since he can fine tune from there for a tight fit. It also gives him some room for error when he routs them.


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## Mcpowell (Dec 19, 2015)

Yes to both enazle and Rich. I wanted the tenon to be slightly oversized so I'd have a touch of wiggle room when routing and it's no problem for me to touch up a little with my shoulder plane. My router seems to have a little "slop" in it when I'm routing all 360º around the collar. It has much less variance when I only rout in one direction.

I did pick up my template at lunch today, so Saturday will be a fun day of set ups, experimentation and tenons!

Hopefully I can finish this weekend, social events are intruding upon my woodworking.


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## Mcpowell (Dec 19, 2015)

Okay, as my service to the community, I wanted to follow up on this thread to show how I decided to make the tenons. Hopefully this won't be too long of a post and the images make it through. I'm sure it's not the only way to make these, but I thought it worked nicely. The only part that could be difficult for other woodworkers would be the metal template. I have access to a laser at work, so I had them cut out a template from .250" stock. If you were careful, you could certainly make the template out of plywood.

Here is my metal template. I've stripped my Leigh D4R pro down and basically am using it as a clamp.










This is a practice workpiece. There is a wedge with double 5º angles being used as a backstop. The work piece is in the middle, and another wedge on the outside. The outside wedge is so my clamp has a flat, instead of angled, surface to clamp against.










Showing one of the 5º angles (A "birds eye view" of the template).










Showing the other 5º angle. The protractor is aligned where the workpiece and the wedge abut.










A walnut workpiece before taking it out of the jig.










Here's the setup with a walnut workpiece. You can see it's sandwiched between the 2 wedges










Out of the jig, but before I clean up the leftover bits.










A dry fit in the chair leg. The angles coming out of the chair leg were correct.










I left the workpiece long, but you get the idea.










Close up of the tenon.


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## Mcpowell (Dec 19, 2015)

And the finished results:

http://lumberjocks.com/projects/397825


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