Dining Chairs

[alcamize]

Need to make a couple of dining chairs here soon so started up sketch up and played around and looked for designs.
Legs will be 2x4, base and back will be 1x4 and the seat will be 3/8 plywood plus cushion that will be decided by the missus.

This is what I've gotten so far
Front View

Side View

Bottom View


I'm not totally sold on this but right now I feel it'd be something doable for me. I'm not sure on joinery right now, I like using dowels for solid joinery but the dining chairs that just broke on us broke along dowel joints. Pocket holes are another option that looks like it would work well here. The back of the chair is half lap joined which will be a first for me but it's still just an option at this point in case I chicken out of it at the time of building.

 

[FlyingRon]

I might try tapering the legs a bit. It looks a little chunky for my tastes right now. I might try reflecting the taper you have on the back down below.

 

[redknife]

Couple of thoughts:
I agree about the taper. I think the back may be uncomfortable without a curve, particularly in a dining room situation. You could use a similar design and bandsaw out the curve from thicker stock.
I worry about the pocket screws without leg stringers, more specifically that the racking force at one time or another would exceed the pocket hole strength. Chris Schwarz makes the point in his book The Anarchist's Design Book that chair stringers aren't necessary provided the joinery is rock solid (paraphrase). In that case he was using wedged through tenons. I could very well be wrong but mortise and tenon would seem a more durable approach for a high use chair.
Lastly, sometimes it is best to find an interim solution so that you can give the woodworking project the time it needs.
Anyway, good luck!

 

[Jeff]

Tell us what kinds of joinery you are capable and comfortable trying? You have tools of some sort...what do you have to work with?

I saw your earlier post on the porch table and this chair design looks a lot like an extension of that idea.

http://www.ncwoodworker.net/forums/showthread.php?t=59154&highlight=porch+table

I like using dowels for solid joinery but the dining chairs that just broke on us broke along dowel joints. Pocket holes are another option that looks like it would work well here.

Give us a few pics of the old chairs (close ups of the bad joints) for a starting point in the new chair design. Maybe the "missus" can give you some ideas about what she'd like to have.

Pics of your current table that you're gonna put these new chairs around? :dontknow:

 

[alcamize]

I'll have to post pictures of the old chairs after work, but they were joined with two dowels at the joints and one simply slipped out and the other broke the dowel inside the joint. All the chairs have been wobbly since we got them and I've had to fix one chair multiple times on the arm (was attached with a pocket hole but used a wood screw that split the wood and stripped a hole in the chair).

We have three of six chairs left from this table so I have time to get this right and replace all the chairs. My tool set includes a circular saw, miter saw, bad jigsaw(bent base) and a hack saw; b&d drill, kreg jig, bench plane and a couple of Wal-Mart chisels I've been practicing with.

I'm comfortable with using screws in a butt joint or with pocket holes and using dowels somewhat. Mortise and tenon I've never done but I've been practicing carving out mortises.

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[Bill Clemmons]

If I were you, Harlee, I would buy enough material to build one chair. Think of that as a prototype. During the process you will answer a lot of your own questions, especially about construction and design. I can almost guarantee you will make changes before you build the final chairs.

 

[JimD]

I've only made pretty easy chairs. My favorites are a Woodsmith design that looks a lot more complicated than it is. All the joints are 90 degree angles. The back slats are curved, bandsawed. Joints are mortise and tenon. I used a plunge router with spiral upcut bit and jigs to make the mortises and the table saw and shoulder plane to make the tenons. You might want to use larger pieces and different joints but the shape is similar to yours with the back legs curved and slanted back.

 

[cyclopentadiene]

I generally do a build with Lowes 2 x 6 SYP to test the shape, height and comfort level. $20 well spent in most cases.

One design feature to consider is most chairs are a trapezoid shape as opposed to square. It is harder to build but allows comfort as one generally spreads the legs slightly and more leg support is more comfortable.

Secondly, the rear leg is generally sloped inward from the floor to the seat and back at the top. I generally use a piece of 8/4 lumber at least 6" wide. The floor of the back leg goes to one side of the board and at the seat meeting on the other side of the board. The upper portion goes back to the same point as the bottom of the leg. On a shorter chair that stops at the lumbar, a 6 inch board is best. A taller chair with the crest rail at the back of he head is more comfortable if designed 7" wide.

Curved lines add grace and elegance. They are no more difficult as you build the entire chair square ensuring perfect fit of the joinery. You can cut the curves, tapers and round over edges after everything is fit. The joinery should be tight enough that you can assemble the chair with no clamps and with a minimal number of clamps, 1 or 2 you can sit in it. The joints on the two rear legs at the seat are most critical.

when completed one leg will always be longer than the others by a few millimeters. You can mark and adjust bu using the table saw as a flat surface.

 

[chris_goris]

Your legs are also going to require stretchers to support them.

 

[JohnnyR]

All the above are good advice (though you could eliminate stretchers with a strong M&T joint). Given your tool set you should make a jig for the circular saw (and get a very good blade) to get long straight cuts with accurate measurements. Gang ALL the backs together to cut your half laps. They'd look better if they were mortised into the sides. Good luck and do the prototype.

 

[tarheelz]

Bah. Chairs are tough. Just make benches.

 

[alcamize]

So using the advice everyone has given I've rough sketched a new design on break.

I'm all for learning mortise and tenon joinery and would be a good excuse to get a nice little saw. I will have to get some wood this weekend and start working on a prototype.

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[alcamize]

These are the broken chairs and the table they go with.

 

[alcamize]

This is the updated sketchup model using the suggestions given. I'm happy with this look honestly although the actual built prototype will be the real judge if I can manage the curves for the back pieces that is. I've also attached the sketchup file if anyone wanted to see that or make adjustments. I've made this using measurements from the chairs I'm replacing, the style will not match the table but I think they will do fine if I can find a matching finish.

 

[chris_goris]

I will reiterate… you need stretchers no matter how you attach the legs at the top. Have a 250 # man sit on that chair and then have him lean back on it, youll find out quickly just how insufficient the structure is. All of the joints have to work together to carry and redistribute the loads. Chair design has evolved over many years into splayed and curved legs tied together with stretchers to carry all the loads. Chairs are one of the most abused pieces of furniture we own, they are used daily, subjected to all sorts of movement and loading conditions, so trying to reinvent the chair in my opinion, is a waste of time and effort.

 

[Dave Richards]

I had a play with your Sketchup file. I fixed a couple of things and then made a few changes.

Stretchers between the legs, the seat rails set in from the outside faces of the legs and the back splats angled parallel to the front edge of the rear legs. As they are in your design, the back rest would be vertical and not very comfortable. I also put a curve on the back of the back splats.



I didn't do it in the model but I would do something with the tops of the back legs to soften the corners. You might consider making the side and front seat rails the same height.

Are you planning to upholster the seat?

 

[alcamize]

@chris_goris stretchers are a good idea but at the time in sketch up I was having enough of a time getting seat rails right that I forgot them.
@Dave I am planning on upholstering the seat but it is another step I'll get to as I figure out the design. The changes you made do look much nicer and I will see what I can do in my file to more match it.

With the stretchers what type of joinery would be usable that won't allow slippage or much slippage?

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[Dave Richards]

@Dave I am planning on upholstering the seat but it is another step I'll get to as I figure out the design. The changes you made do look much nicer and I will see what I can do in my file to more match it.

With the stretchers what type of joinery would be usable that won't allow slippage or much slippage?

You could use loose tenons for the joinery.

 

[alcamize]

I see the added curve you did on the backer on the chair. Loose tenons would be something I can do, I see if I can make a little jig to practice it first. This will definitely be a learning experience.

 

[Willemjm]

If I were you, Harlee, I would buy enough material to build one chair. Think of that as a prototype. During the process you will answer a lot of your own questions, especially about construction and design. I can almost guarantee you will make changes before you build the final chairs.

LOL, that is exactly what I always do with a new chair design if I have to make 4 or more. I build the prototype, then actually live with it for a couple of weeks until I decide it is either a marriage, or a divorce.