BtZ42 p.4 - curved spokes

[ish mailian]

 http://www.elevatorpreservation.com/2013/09/recognize-this-curved-spoke-wheel/

On Sun, Mar 20, 2016 at 3:19 PM, David Morris <fqmorris at gmail.com> wrote:
> http://www.freepik.com/free-photos-vectors/yin-yang
>
> Yin Yang is a single S-shaped spoked wheel.
>
> David Morris
>
> On Sunday, March 20, 2016, Monte Davis <montedavis49 at gmail.com> wrote:
>>
>> Maybe not just a design style: according to a machinists' blog, curved
>> spokes were functional in cast-iron flywheels, pulley wheels etc.:
>>
>> "Spokes shaped like an S, a spiral, a set of semicircular arcs, all do the
>> same thing - allow some needed compliance so that the spokes or rim don't
>> fracture when cooling [and shrinking at different rates depending on
>> thickness, shape, position]... Steel or aluminum have more favorable
>> stiffness to strength ratios or, perhaps more importantly, more available
>> plastic yield before fracture, and are therefore not so fussy about
>> shrinkage. And forged, wrought, or fabricated wheels don't have the same
>> shrinkage problems that castings do. But back when cast iron was king,
>> shrinkage fractures were a constant headache."
>>
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Pynchon-l / http://www.waste.org/mail/?list=pynchon-l