Thread: Zigzag chair with 22.5° mitres and Domino joinery - WIP

Looking good David, as do all of your projects.

Do you think it will be as strong a joint as the keyed one you made for the get-together last year?

I can understand your wanting to speed it up by using the Domi, but...

Skew,

I think it will be almost as strong, because the three reinforcing tenons will be pinned with two brass 1/8" rod pins. These pins will penetrate all three tenons, as described in the thread on the prototype mentioned in the first post of this thread. These pins should prevent the tenons from being torn out of their mortices. But I am hoping, if the chair goes together properly, to test it at another gtg by getting three forum members to stand on a plank on the chair. If it passes that test easily, I might offer up a prayer and load a fourth person onto the plank. I have also made another zigzag chair with mitred bridle joints which can be tested similarly. I am more confident that that chair would easily pass the four-person test.

Rocker

Oh Doubting David! Thou should have greater faith in the Domi!

I should've read the other thread...

Still, I'm hoping someone makes a video of the tests at the next gtg for the vid thread. It should be interesting footage whether the joint passes the load test or not.

Steve,

I am pretty confident that the chairs will pass the test, but I have to admit that the joint is probably not quite as strong as the one tested last year, which had two 1/8" rock maple keys and was similarly pinned with 1/8" brass rod. On the other hand, this test will be less rigorous, since there will be a whole chair bearing the weight, rather than a single joint, and the twisting force, which caused the partial failure of the joint in the previous test, should not be a factor in a complete chair.

Rocker

The picture shows the 28mm deep twin mortices for the reinforcing tenons; a single mortice is cut from the other side of the joint, so that there are three reinforcing tenons in each joint. Two 1/8" brass rod pins will penetrate all three tenons. The clamped-on backing piece ensures that the plate of the Domino can be held down flat without wobbling up or down.

Rocker

Very interesting Rocker!
Are these going to be the same as the kangaroo chair you made before or are there a few changes?

Harry,

Yes, the design is the same - only the joinery is different.

Rocker

Rocker,

Very nice joinery... I like it!


Matt

The picture shows the back stiles being glued to the seat side rails; the 49° mitre joints are each reinforced by a single 8 x 50 domino. Two brass pins, one on either side of the mitre face will lock each tenon in position. Note the reinforcing tenons in the zigzag mitres, which have not yet been trimmed flush.

Tomorrow, the side assemblies will be sanded, and their edges eased, and then the back rails, seat rails, and stretcher will be glued between them. and the chair will be finished, apart from the frame for the upholstered seat.

Rocker

You are one very productive man, David. What do you do in your spare time?

Don,

As you have no doubt found also, I don't have much spare time now that I am retired. Now that I am beginning to see the dark at the end of the tunnel, I realize that I have a large box of dominoes to use up, and not all that much time to do so

To answer your question, I play Bridge and Sudoku against my computer, talk to seppos and poms on IRC, and generally mess about trying to avoid house painting and suchlike honey-do's.

Rocker

The 1/8" brass locking pins have been glued in place with epoxy, filed level, and sanded, and the side assemblies were sanded also. The picture shows the glue-up of the chair, using twelve 8 x 40 dominoes and Techniglue to glue the cross rails between the side assemblies.

The chair, together with another zigzag chair made with mitred bridle-joints, is ready for testing at a gtg that I propose to hold at my place in late October - for details, see the Announcements forum. So, if you wish to witness this momentous event, get your booking in.

Rocker