Piano Key Inertial Balance

[Richard Brekne]

Ahh... so you went public.. !! good for you Mark..

As long as we are on this... I suggested trying to use magnets instead
of springs. I understand there is a problem with this idea because of
the non linearity of magnet strength for distance vs the linearity of
springs... but since we have some informed minds on line... answer me
this..

if you had two sets of magnets mounted on the spindle and appropriatly
mounted opposing magnents on the frame... then would not the net force
on the mass being measured always be the same ? I mean as the spindle
moved away from one side that magnet pair would decrease in force in
exactly the same degree the the other side would be increasing in
strength.

It just struck me as potentially more stable to use neodym magnets
instead of springs.

Any comments ??

RicB

Mark Davidson wrote:
> 
> RicB wrote:
> >Maybe Mark will find this a good time to make public his key MOI
> >measureing device. Open sourced... we can collectively refine it to a
> >useable and easy to build yourself tool. That way more of us can work on
> >this puppy
> 
> Alrighty then.  Here it is.. spell checked and everything.  I'm sure
> there'll be many questions - don't hesitate to ask (just please read it all
> the way through first). Exact measurements for the most part are not
> critical so not many are included.   Oh yeah, and I used the word "inertia"
> loosely throughout to mean the moment of inertia, so just get over it.
> 
> http://home.mindspring.com/~mark.davidson/inertial_balance.htm
> 
> -Mark
> 
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