Joinery for a zigzag dining set

[David Dundas]

In another thread, http://www.bt3central.com/showthread.php?t=39681 , Popeye posted a Z-chair that he had adapted from my design, which is described in an article on the FestoolUSA website. My Z-chair is part of a dining set, see photos 1-3.

I have experimented with several different ways of making the miter joints for these chairs. The easiest method is to use the Festool Domino tenon joiner to make the joints, and use shop-made matching tenon stock, as described in the article, see photo 4. If you don't own a Domino, you can use a precision mortising jig(photo 8), which is described in an article on my blog (see below), to rout a mortise for a single through reinforcing tenon, see photo 5. Alternatively, you can use a micro-adjustable table-saw tenoning jig, also described in an article on my blog, to cut twin slots for reinforcing splines.

The original version of my chair used bridle joints (photo 6), rather than miter joints. The bridle joints were cut using a dado set and a tenoning jig, see photo 7, to cut both the tenon and the slot for the bridle joint.

David Dundas

[David Dundas]

In case you are still sceptical about the strength of these chairs, here is a picture of three men, weighing a total of about 500 lbs, standing on one of them.

David Dundas

[Crash2510]

that is awesome.

very nicely done. I can't believe those are that strong.

oh and welcome to the best forum on the net.

[Stytooner]

Welcome aboard. Nice design, BTW. I used to go to parties were folks were dancing on the furniture. They would be at a different place each time. Likely because we never got invited back.

I really like the armed chair version. It looks more balanced to the eye. The bridle joint looks the best to me as well. I really like that kind of look especially in oak.

I saw a version you made that was a rocker.
Now that was very cool too. Great stuff and keep on posting.

[jackellis]

David,

How much do the legs flex? Not at all, a little, a lot? I have a very comfortable chair made out of bent wood (store bought) that flexes a bit when I sit down or get up. Seems like the Z chair do the same.

[shoottx]

Welcome to the site.

Great design and execution of a concept.

But three aussies standing on a chair with no beer in their hands ? I don't believe it!

[drumpriest]

Hey David, I have a domino, and love it, but here in the states I can't find router bits to radius my tenon stock correctly. I assume a 4mm (I use 8mm tenons mostly) is available outside of the us??

[Popeye]

Hey Mark, I guess I didn't say it before but THANKS for the great design and publishing the plan for it. Pat

[leehljp]

Welcome and push more of us along to doing this kind of work. We have lots of capable people here.

Beautiful work!

[cabinetman]

That's impressive joint strength. Did the three of you try jumping up and down...just kidding. Actually, I like the looks of this joint:
.

.
Did you consider a full half lap?
.

[David Dundas]

Hey David, I have a domino, and love it, but here in the states I can't find router bits to radius my tenon stock correctly. I assume a 4mm (I use 8mm tenons mostly) is available outside of the us??

Drumpriest,

It is not too critical for the radius to be exactly right when making shop-made tenon stock; a 3/16" radius bit works quite satisfactorily for 8 mm tenon stock.

Cabinetman,

I dont think a half-lap joint would be nearly as strong, since there would be much less glue area, and IMO it would not look as good as a bridle joint either.

Incidentally, I have now come to the conclusion that the brass pins I used on these chairs do not add materially to the strength of the joints, and may in fact weaken them, although they provide a nice decorative feature.

David Dundas

[David Dundas]

I really like the armed chair version. It looks more balanced to the eye. The bridle joint looks the best to me as well. I really like that kind of look especially in oak.

I saw a version you made that was a rocker.

Stytooner,

I think perhaps the carver chair looks a bit more like a traditional chair, and so appeals more to traditionalists. My inspiration for the armless chair was Gerrit Rietvelt's famous Zigzag chair, wich is just made of four flat boards. That chair is striking in appearance, but totally impractical as a serviceable dining chair. My aim was to echo Rietvelt's form, but make the chair comfortable.

The rocker you refer to is pictured below, with a close-up picture of its splined miter joint.

Jackellis,

The legs of the Z-chairs do flex noticeably, which adds to their comfort.

David Dundas

[drumpriest]

I typically use a 3/16, but I figured if I was going to expose the tenon, it might not look the greatest. 5/32 is much closer, I may pick one of those up and give it a try.

[jspelbring]

Mortises

David,

Thanks for the great posts on this. I have to make one of these now! I recently got a JP combo that has a slot mortiser on it - I'll either use that, or try the bridle joint that you showed.

Awesome work!

[SARGE..g-47]

Nice design David.. I am behind and just commented on the chair Popeye posted...

Regards from up the road NW of Popeye.