Re: I was trying to "Engineer" chairs

Derek Cohen (in Perth, Australia)
Barry, Dick makes some good points, above.

Over the past few weeks I built a prototype stool for the kitchen. This was a whole new world of learning for me. Not only was it necessary to carve a comfortable seat, or design aesthetic-looking legs, but calculating the number of legs (3 vs 4), their resultant angles (combination of splay and rake), and THEN how to brace them ...

Bracing could have been separate stretchers to each leg, as in this Estherick stool (I like very much) ...

... which made sense to me on an intuitive level since it triangulated the legs.

I went with a different design in the prototype.

I thought that this would be slimmer (I don't anymore), but had initial reservations since the rear leg did not receive support from the sides (as in the first design). Then it dawned on me that the force vector on the rear leg is straight back, not to the sides, since that is its angle. The T-stretcher simply prevents it stretching further than it should, and in turn prevents the front legs doing the same. The front cross stretcher prevents the legs splaying further. It is the combination that strengthens the legs. In practice, it is as steady as a rock.

(My wife did not like this prototype).

Regards from Perth


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