Joinery likely in the Thos Moser "Ellipse" stool

[Gene Davis]

Here is a photo of Moser's "Ellipse" stool.

The seat is solid stock, shaped with a saddle depression as shown.

Stretchers are tenoned into the legs, and I am wondering if the leg mortises are done as a shallow round bore, then a square mortise inside. This, to eliminate the work of doing shaped shoulders to match the curve and taper of the legs.

The larger top stretcher-supports have small span supports between, two of them, which support the seat. I think three screws each, the two outermost ones in slotted holes, up through these to fix the seat on.

I threw a preliminary doodle of this up on the 3D Warehouse, after doing a study of the 25" high version, using Sketchup. My model is missing the two cross members under the seat.

For machining the thick blank for the seat, hogging most of the material away before going after it with a grinder or hand tools, I envision a couple fixtures and a router sled. Fixtures also needed for machining the mortises into the legs.

[Jamie Buxton]

You have round stretchers. Why not just drill round holes into the legs, and stick the round stretchers in?

The seat supports could also have no shoulders. The mortise would be cut in the leg by a slot mortiser or a router with a simple straight bit.

The seat looks like it is covered with leather or vinyl. Why not make the shape with plywood? You'd have no expansion issue, and no worries about splitting. You could make it a bent lamination, and get the curve without any carving. That is likely how a factory (for instance Moser) would do it.

[Gene Davis]

Thanks, Jamie, for the insight. I remember having a thought that the seat was leather-covered, but the pic just isn't that clear, and I got fixated on it being wood. Something really dark, all softened up around the perimeter edges with hand tools.

Of course it is leather. Yes. Thanks.

And the core for it could be a stack of veneer, all glued up and formed with the curve, maybe in a bag press or just a hard press with forms. This custom-formed "plywood" core could be then cut and shaped, and sent to the leather guy to do his upholstery magic. A shoemaker could do it.

I worked some more on the model and put the seat supports in. The Thos Moser site has a downloadable .pdf spec sheet for the chair that was helpful in understanding its construction. The seat supports are seen in one of the diagrams.

[Gene Davis]

And here is a view of my model to match up with the drawing shown in the Moser tearsheet. I have a few discrepancies, but I think the overall scale is right. The countertop stool height (25" approx seat height) is the one we are after.

My legs are 1.5 dia at top and 0.75 dia at bottom. Stretchers are 5/8" dia. Seat support rails and stretchers are 0.75 thickness.

A close inspection of other stools by Moser, done from photos at the website, show round stretchers having turned-down tenons so as to go into holes in legs smaller than stretcher diameter. This stool is an exception. Note in the Moser tearsheet diagram that the stretcher mortises in the legs are pretty shallow. Too deep, and you remove too much from the leg section, weakening it.

Note also my seat is quite thick as compared to the Moser one. I am now thinking I like my thicker seat (7/8" in my model) and may try it as solid wood rather than upholstery over a core. Wood, I can do. Not so much upholstery.

I only have a 14" bandsaw and so would rough-saw curved blanks for a seat like this, maybe three at about 5" width, then glue up to get the width, and shape from there. Walnut seat, cherry everywhere else.

[Jamie Buxton]

... Stretchers are 5/8" dia. ....

On a stool that tall, sitters will certainly be resting their legs on the lower stretchers. That's a fairly substantial load on a 5/8" dowel. Somebody might even be inclined to stand up to reach something, while still standing on that lower stretcher. That'd be a very big load on a 5/8" dowel. For more strength, you could keep the stretchers round, but turn them thicker in the middle than they are at the ends. Or you could make them more like the seat supports.

[Dave Richards]

Be aware that those tear sheet drawings aren't perfect representations of the actual pieces of furniture. I found that out a few years ago when I was doing some work for them.