Hello All;

This Is All quite Interesting but no one
seems to concentrate on the real
devil your fighting which is gravity.

In order to lengthen the period of a pendulum
you must find some way of lowering the pull
of gravity which is 32.17fpss that means you need
to effectively reduce it to like
3.217fpss if you want a decent period.

At least that is how I understand it.

All these fancy things we do are essentially to
reduce gravitational effects on the mass.
 You might use bouyancy to help you
if you can find a fluid with high specific gravity
like 5g/cm3 or more then use a small spring to do the rest
on the mass.

Whatever you can get to oppose gravity is in the game.

If only someone could find a cheap way to oppose gravity ??

Light ( EM ) waves are themselves like a pendulum
in that they oscillate seemingly between the potential ( E )
and the Kenetic ( B ) and who is to say there is nothing to
dampen an EM wave since we simply can not ride with one
till it dies out ???

Just a thought stimulated by this thread.

Regards;
geoff
----- Original Message ----- 
From: 
To: 
Sent: Saturday, October 27, 2007 4:20 PM
Subject: Re: Different types of Pendulums


> Hi Folks,   I found the wed site again. 
> http://www.phy.mtu.edu/~suits/PH3110/pendulums.html  The two I mentioned are 
> called "Balanced-Like" and "Nearly Balanced"
> Just wondering if anyone has worked with them.  As I said I made a mock up, 
> with no luck.  But maybe my mock up was not done correctly.
> Ted
> 
> 
> 
> 
> 
> 
> ----- Original Message ----- 
> From: "John Lahr" 
> To: 
> Sent: Saturday, October 27, 2007 4:04 PM
> Subject: Re: Different types of Pendulums
> 
> 
>> The "airplane-type" design is basically a "solid pendulum."  Although the 
>> period can be made
>> very long, the sensitivity becomes correspondingly low.  I don't recommend 
>> this design.
>>
>> Cheers,
>> John
>>
>> At 02:44 PM 10/27/2007, you wrote:
>>>In a message dated 27/10/2007 22:23:56 GMT Daylight Time, 
>>>tchannel1@............ writes:
>>>Hi Folks, Sometime in the past I saw a web site describing different types 
>>>of pendulums used in sensors.  I don't remember their names, but
>>>
>>>1.  one was a long vertical rod, with a center pivot, it contained a mass 
>>>at the top of the rod and a mass at the bottom of the rod.
>>>
>>>My question has to do with 1.  I thought this pendulum (positioned like an 
>>>airplane propeller) was able to adjust it's period by moving the top and 
>>>or bottom mass, up or down the rod?
>>>I made a simply mock up of this illustration, but was not successful in 
>>>any way. Can one adjust this arrangement to result in an extended period? 
>>>Does anyone know of this web site or one similar?
>>>
>>>Hi Ted,
>>>
>>>     There are several possible systems, but you need to suspend the 
>>> pendulum near the middle, a small height above the centre of gravity. 
>>> This gives a high moment of inertia due to the masses at the ends and the 
>>> small restoring force due to 2x mass operating just below the suspension 
>>> axis. It should work fine. You can also vary the position of one of the 
>>> masses.
>>>
>>>     Regards,
>>>
>>>     Chris Chapman
>>
>>
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