Prototype Shop Stool

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Snettymakes

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I have some Ash that I was to use to make a workshop stool, but as I have no experience with chair/stool making I decided to make an (overly elaborate) prototype from baltic birch.

I immediately fell into a trap of creativity with complexity that couldn't possibly be part of the future final stool. I liked the idea of the plywood pattern on all 4 faces of the legs, which involved planing off 1 veneer, gluing up pieces to make double thickness (~1.5 inch) stock and then cutting legs from each. I'm quite pleased with it from a creative standpoint, but I could have been finished weeks ago so 🤷🏻‍♂️.




I wanted to try out a brace design that I have in mind for the ash stool. For once I managed to contain my urge to overcomplicated the joint and it went together nice and easy with butt joints and through dowels. The roundover bit on the router table wouldn't reach into all the corners, but some hand tool work with a file sorted those out quickly.

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I don't have any shorts of forming the tenons on the legs unfortunately. I pondered how to achieve that without a lathe and eventually found that a 10mm round over bit did a decent job. Time for a dry fit, and this is where life became a bit tedious and I felt like I was likely to screw up the project. The brace detail meant I had to decide between rotating the legs slightly so that the brace pieces would sit flush with the legs, or angling the joint. I went for rotating the legs which I think was the correct aesthetic, but was a pain in the ass to get them to the right angle all the way around. Of course every time I needed to remove the legs, I'd screw up the angle. The mortice and tenons were very snug too, which meant pounding them in with a mallet (which does not aid precision). I did find though that by twisting the legs as I hit them with the mallet, I could tune them in very easily, which at least meant I didn't need to take the legs out entirely to reposition them.

Annoyingly I discovered that once I'd cut the slots for wedges, this loosened up the joint such that inserting the legs could be done very easily by hand and tuning the angle was just a matter of twisting 🙄. Oh well, that's a lesson to file away.

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Time for glue up, more butt joints and through dowels for the braces. This went better than expected, although one joint ended up a little opened up. Plenty strong with the dowel though I think.

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After glue up, a final sanding and on to finish. I was eager to be done, so a couple of coats of blonde shellac with a quick sand was the chosen finish. It does bring out the less noticeable grain details nicely in the birch veneer.

tempImagel7feAj.png tempImageQp9flJ.png tempImage00vVyD.png
...and it's done!

I'm relatively happy with the design. I didn't want to shape the seat because the nature of a shop stool is that it gets grabbed without looking and I didn't want to have to worry about which direction it's facing. I would probably round the seat corners considerably more, and I had intended to curve the edges (somewhat like a plectrum), so that will happen in the ash version.

The legs..... oh the legs :(. There is considerably too much twist. It doesn't feel like I'm likely to break it, but when sitting on it and twisting, the seat will move a fair amount. I suspect that this is a combination of leg thickness, and material (I'd like to hear opinions on this please). Possibly the rake (is that the correct term for the angle?) of the legs is a little too acute also.

The leg brace does not function as a foot rest very well, it would be considerably more comfortable to just have braces directly between each leg. I think in terms of design, I would make the overlap much tighter, so that the triangle in the middle is much smaller, but I need to consider whether the function of the foot rest is more important than the aesthetic (probably).
 

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novocaine

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twist will be due to your brace and you leg splay. with the brace (which does look lovely) you've created 3 levers that all act as you twist your weight to distort the triangle.
interesting design, add another brace between the legs (or you might get away with a second one similar to what you've done, but the other way round) and I think you'd be good to go really, I like idea of an almost convex top, but I'd always feel like I was slipping off it. :)
 

Snettymakes

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twist will be due to your brace and you leg splay. with the brace (which does look lovely) you've created 3 levers that all act as you twist your weight to distort the triangle.
interesting design, add another brace between the legs (or you might get away with a second one similar to what you've done, but the other way round) and I think you'd be good to go really

I wondered. Interesting idea to add another one. Turning it the other way around will result in a joint that is not square, meaning I should have had a "not square" joint on the other, and had the legs square to the points of the seat. It's only a prototype, so that's ok, but a note for me for the next one.

I'll wait and see what others think, but at the moment I think I'll add another brace to see whether it makes a difference.
 

Fitzroy

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Love the shape/form, and especially the thick plywood top. I find the legs and top ply combo a little too visually busy, and think it would look great with solid wood/painted legs. From an aesthetic view point I find the legs are too light compared to the top, and a fraction more rake/splay would benefit. Thicker legs and more rake/splay would also help with the stability. As you say the brace is not great as a foot rest but it looks fab, hmm how to make it work as both!
 

paulrbarnard

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Love the shape/form, and especially the thick plywood top. I find the legs and top ply combo a little too visually busy, and think it would look great with solid wood/painted legs. From an aesthetic view point I find the legs are too light compared to the top, and a fraction more rake/splay would benefit. Thicker legs and more rake/splay would also help with the stability. As you say the brace is not great as a foot rest but it looks fab, hmm how to make it work as both!
I had the same thought on the legs. They need a bit more mass to balance the seat.
love the brace, it looks great even if it comprises the rigidity a little. Heavier legs would offset that too.
 

Jacob

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Legs needed splaying = "triangulated" and inherently stable.
Or parallel legs lie your design are doomed to flex unless you triangulated them instead, with diagonal braces of some sort like a "girder"
 
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Snettymakes

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Crux question… is it comfortable?
Sorry if you’ve said and I’ve missed it

I've not used it for any length of time, so I'll have to see. I mean, it's a solid piece of wood with no moulding, so I'm expecting "not particularly". Your question has made me consider this for the ash version though.. I may experiment some more with shaping this top.
 

Snettymakes

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Legs needed splaying = "triangulated" and inherently stable.
Or parallel legs lie your design are doomed to flex unless you triangulated them instead, with diagonal braces of some sort like a "girder"

My legs are splayed 8 degrees. I'm guessing you're saying that they need to be a less acute angle?
 

Jacob

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My legs are splayed 8 degrees. I'm guessing you're saying that they need to be a less acute angle?
I guess so. Have a look at some other three legged stools?
Most of them have the legs extending well beyond the plan of the top which makes them inherently more stable.
In your photos they don't look splayed at all.
Screenshot 2021-08-03 at 15.51.08.png
 
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TheTiddles

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I've not used it for any length of time, so I'll have to see. I mean, it's a solid piece of wood with no moulding, so I'm expecting "not particularly". Your question has made me consider this for the ash version though.. I may experiment some more with shaping this top.
I can’t but help think it will matter!
 
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