Bill Freeman wrote:

Paul,

Do you think there would be any interest in me putting
together an XL spreadsheet with some of the std
engineering calculations built in so the user could just
change the input values, in labeled fields, to get the
answers?  I'm a bit leery of this because certainly some
ignorant user (no slander, we are all ignorant of something,
and ignorance, unlike stupidity, is correctable) will
use it incorrectly.  I suppose it is like any other power
tool --  if you cut your arm off with a skilsaw, it is not the
saw's fault (except in certain courtrooms).  There's always
the units issue, too.  But it might help some.

OTOH, perhaps they should buy a Schaum's Outlines
"Strength of Materials", or "Engineering Mechanics"
perhaps the best, cheapest and most direct outline
version of engineering technical texts that I have
found.  Most people balk at the outrageous prices
of today's textbooks (~$90 !).  Schaum's, in paperback,
and in terse, no details outline format serves a real
need, it seems to me.  Lots of worked examples with
the answers, too.  I recommend it to those readers that
desire some education in this area at a reasonable price.
Published by McGraw-Hill, probably need to order them
except at university bookstores.

May have some time between Xmas and New Yrs, so
let me know what you think.

Bill

I think it is a good idea Bill. I now have an XL compatible
spreadsheet on my Linux box :-) I really like the Schaums books
that come with integrated computer solutions on an enclosed
CD.

BTW I think we have homed in on a problem with the PSRU shaft.
Seems the gust response of a home built airplane is a major
factor. Specifically the rate of pitch change numbers seem to vary
over a wide range. One radian per second comes up often.  I suspect 
it has a lot to do with the polar moment of inertia through a lateral 
axis at the CG and the wing loading. Perhaps this is why the VW engine in airplanes
had so much trouble with broken cranks. Low polar with low
wing loading?

Got any input on this? Got any numbers on common homebuilts for this kind 
of polar moment of inertia?

Another question for you. Does the torsional response of a flywheel
shaft system vary with the rate of change of the forcing frequency
pulse or just the amplitude and frequency?

Paul Lamar
 
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