pdp1@EARTHLINK.NET on wed 13 jul 05
Oh! Good call Vince...
I clean did not take into account the shrinkage in the Mould of the cooling
Cast iron, being a
probable factor for the "S" Spoke...
Makes perfect sense...
After a while of course, that matter was resolved one way or another with
experience, impirically in the use of various alloys of Iron, as for the
problems of a straight spoke causing problems in the Mould...
Nice call though...
I'd have enjoyed seeing that fellows old Machines, and yours before you got
rid of them..!
Phil
in Sunny el ve
----- Original Message -----
From: "Vince Pitelka"
> > I've always wondered if the beautiful S shaped spokes of
> > vintage wheels, sheaves, etc were made that way for just
> > their beauty or was their an engineering reason behind it?
> > Or, was this just an old time marketing ploy to imply
> > greater strength?
>
> Earl -
> Having been a serious student of antiquated technology for most of my
life,
> and having an extensive library of old technical volumes, I can answer
that.
> Initially the S-spoke was a purely practical innovation. In early
> Industrial Revolution iron casting technology, differential shrinkage in
> large flat disks caused serious problems with cracks, and a wheel with
> straight spokes is just a large flat disk with a lot of the unnecessary
mass
> removed. When cast with primitive technology, it is still subject to the
> same shrinkage problems. Before steel and refined maleable iron, S-spokes
> could absorb differential shrinkage and shock while straight spokes could
> not.
>
> That said, it is certainly true that machinery designers and builders
almost
> immediately developed an aesthetic appreciation of curved spokes on
> flywheels and handwheels, and they became far more than a purely practical
> feature. There's a tremendous variation in design of curved spokes. In
> some cases, they are each just a single arc, while in other cases they are
> each S-curve, and in some cases the S-curve can be pretty dramatic.
> Handwheels for operating machinery often featured very beautiful, graceful
> S-spokes.
>
> When I lived in California I was a serious machinery collector, and among
my
> various collections were several dozen old curved-spoke flywheels and
> handwheels - I just had them hanging on a wall of my shop, and they were
> beautiful objects. When Linda and I left California to go to grad school
in
> 1985 we got rid of 90% of everything we owned, including many tons of
> collectible iron - post drills, pump jacks, flat belt machinery, old
> single-cylinder gas engines, vises, anvils, etc. I will never regret
that,
> but I do miss some of those objects and machines. I kept a collection of
> old brass steam whistles and gauges, and I also still own a 1905 DeLaval
> Dairy Supply 2 HP horizontal single-cylinder gas engine with water hopper,
> twin flywheels, and make-and-break ignition. It weighs 750 lbs., but
those
> were honest horsepower.
>
> But I digress.
> - Vince
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