[TheForge] Re: Off-topic: ...dynamic balancing, vibration...

[Mike Spencer]

> If we assume 2 absolutely identical flywheels mounted on a shaft and
> assume that each flywheel has a heavy side but that each heavy side
> happens to be located 180 degrees apart from each other it is
> possible for the 2 flywheels and shaft to balance in a static
> condition but the assembly will never be in balance dynamically. The
> longer the shaft the more difficult the problem becomes.

And the longer the shaft is, the more important it becomes that, under
this condition and at high RPMs, the shaft is trying ardently to
assume a more or less sinusoidal shape.


FWIW

-- 
Michael Spencer                  Nova Scotia, Canada       .~. 
                                                           /V\ 
mspencer at tallships.ca                                     /( )\
http://home.tallships.ca/mspencer/                        ^^-^^