Help needed with stool design

[xy mosian]

Hi all, I am on the verge of making a stool similar to the one shown.

Just in case the dimensions are not readable. The top/seat is 330mm x 220mm. with a thickness of 30mm. Height is 334mm. My problem is the distance of the leg holes from the edges of the top. As shown the legs are 35mm from each edge. Are these dimensions enough? The top is Oak and the legs will be Oak or Ash. The tenons will be tapered with the small diameter at about 18mm.
Thanks in advance xy.

 

[Spindle]

Hi

You don't indicate the splay of the legs but from the design I'd say it would be OK as long as it's not abused - overloaded or rocked on to two legs etc.

If the splay angle is greater than 15 degrees I'd be looking to move the mortices inboard and also to increase the diameter of the tenons.

If you don't wish to increase the size of the tenons you could add a set of stretchers to the legs.

Are you planning to wedge the tenons - if so remember to have the wedges orientated across the grain of the seat.

What ever you do have fun

Regards Mick

 

[xy mosian]

Thanks for the response Mick.
The 'sight line' splay angle actually worked out at 14.5 degrees, the angle in the leg plane will be less. There of course is the snag, with the foot end of the leg outboard of the seat, for stability, as the tenon is moved inwards, the splay angle becomes greater, leading to greater splitting forces.

I am going to use stretchers, my plan at the moment is a H stretcher with the sides of the H along the short dimension to re-inforce the grain. Sorry I didn't mention, the grain of the seat will run along the longer dimension.

The tenons will be a taper fit, I don't think a wedge will be needed. With the taper I have, I recon that an 18mm hole in the top of the seat will give a 'big end' diameter of about 21 mm.

Could you give me some insight into your mention of 15 degrees. Is this a known, by others at least, angle or is it from experience. It certainly feels sort of 'right' to me.

Thanks again, xy

 

[Spindle]

Hi

I'd have no issues with your design in view of the fact you intend to add stretchers - a traditional 'H' set up as you describe or have you considered the little more unusual 'X' type?

The taper tenons will be fine and I agree, they should end up in the region of increasing to 21mm. Technically they will not require wedging but if they are to be through tenons, and therefore on display, I feel the wedges add that bit of extra interest. How do you plan to make the mortices, do you have a tapered spoon bit?

The 15 degree sight angle is about where things begin to look 'wrong' to me if there are no stretchers - to be honest, most things without stretchers have me looking twice and mentally weighing up the stresses and centre of gravity. I have several books on traditional chair making but have never seen reference to a go / no go angle for stretchers.

Regards Mick

 

[xy mosian]

Hi Mick,

I appreciate your thoughts, thanks.

An 'X' type stretcher? It takes me long enough to actually start something anyway. That would take a lot of thinking about, and might delay me even more. Could you point me at an image please?

I made a tapered mortice device, after reading about one somewhere on the 'net. It is basically a tapered wooden dowel with a scraper slipped into it. I used a stringy hardwood and this left a bit to be desired. The first time I used it I lost a little at the very end. It has no effect at these sizes.

Once having made the mortice, scraper? I used it to make a tapering device for leg ends.

I seem to be having trouble loading images but they appear in this thread a-windsor-chair-in-france-sessions-1-4-t70651.html

That chair was based on lots of research, well looking a images on the web. And was built by seat of the pants flying, I'd like to give this stool a little more consideration.

I take your point about rake angles just 'looking wrong'. One of the problems I have with some modern American windsors is the widely spread legs, but then a lot of them use, to me, a thick softwood seat. Presumably the softwood needs the tenons further in for strength. This will lead to a widely splayed leg to get the foot outside the seat area. I much prefer what I think of as the 'English' more upright leg, they look much less like that unfortunate Giraffe, that did the splits.

Regards, xy

 

[Spindle]

Hi xy

Here's an 'X' stretcher - not on a stool but you'll get the idea. They sometimes have a sphere or a toroid at the central intersection:

Thanks for the link to your Windsor, it must have been very rewarding to have made something like that in such a nice environment. I like your method for producing tapered mortices, I may adopt it rather than fork out £50 for a spoon bit - to date I've used parallel tenons.

I couldn't agree more with you regarding the American Windsors - I visited Winterthur once and some of those chairs defy logic when seen in the flesh

http://miraimages.photoshelter.com/imag ... 73z423RlZw

Regards Mick

 

[xy mosian]

Hi Mick,
My Windsor was made in deepest Charente, I was the noisiest thing around. I would have preferred more time and a little more timber. Still a great learning experience. I have since changed the front legs to an elongated rugby ball shape, it does look better but the leg front leg plane is a little twisted. Rustic eh?

I cannot claim originality for the reamer. From memory I spotted it used in a Roy Underhill video, and then tracked down Elia Bizzarri http://www.handtoolwoodworking.com/tools.html. The link for use is worthwhile as is the link to Jeanie Alexander's page http://www.greenwoodworking.com/SawStee ... eamerPlans. I am sure a similar, shorter, device could be produced for blind holes, stretcher tenons perhaps?

Preparing the wooden blank was fun. Drawing the lines for the saw cut took some head scratching. If you do decide to make one, don't hesitate to get in touch in the unlikely event of you getting stuck.

Now to 'X' stretchers. Thanks for the image. I have seen similar on occasional tables, I think, with a turned cylinder at the centre. I'm still pondering that one.

Regards xy.