On Nov 11, 2007 7:40 AM, Randall Peters <
PETERS_RD@..........> wrote:
Hi Randall and all,
Your eddy current damping statement below is interesting and likely applies. Anyway;
I proceeded with some more experimentation today and put up 3 more pictures on the same web page:
I put the magnets atop the steel block "mast". This makes it alot easier to manipulate the
magnets/mechanics.
I added some soft iron spring material I salvaged from (I think) a Kodac disposable camera, and
that helped alot with regard to the free oscillation time which was about 70 minutes plus. It
spend alot of time (~20 minutes) oscillating when it was less than a 1/32" total span; which
essentially means it would be quite effective as is for a amateur horizontal enertia pendulum.
Meredith Lamb
Meredith,
You mention 'standard' crossed rods oscillating up to about 4 times longer than your present arrangement
with magnets. If your 'standard' setup has no magnets, then I predict that a big part of this difference derives
from eddy current damping due to the induced currents in the steel rods as the oscillate in the strong magnetic
field of your gold-coated units. This eddy current component is not a 'show-stopper' like the mechnical
internal friction parts. It is actually advantageous.
Randall