[TheForge] Chimes

[Erik Gutfeldt]

Mike Linn,

So the node at 22.42% of length comes from a solution to a 4th order  
differential equation. No wonder it wasn't intuitively obvious. I  
haven't used math like that since college, and have forgotten it for  
the most part. I haven't had a need for it in many years of electrical  
hardware engineering or a hobby of blacksmithing. Fun to see that there  
IS an answer to WHY, Thanks.

Tho I suppose this is getting a bit off topic for a blacksmithing list  
;)

Mike Spencer,

I look forward to 'hearing' how your bomb site sounds when you try it.

Erik

(obviously there's at least two Mikes, any other Eriks with a k out  
there?)

On Sep 17, 2004, at 5:43 PM, Mike Linn wrote:

>
> Erik
>
> That is because the natural frequency of the chime is based on length  
> AND diameter..  The wave physics you remember from high school or  
> electronics is for a string or zero diameter wave. For a string, the  
> diameter is a negligible influence on the node location and for zero  
> diameter waves, it is theoretically at the 1/4 wave length. According  
> to Euler's Equations  
> (http://www1.iwvisp.com/cllsj/windchimes/euler.html) the nodes are  
> based on the mass per unit length in other words length, diameter and  
> wall thickness all play a roll, to varying degrees.
>
> Here is another site for info on chime calculations and a few tips on  
> the clapper.  http://www1.iwvisp.com/cllsj/windchimes/
>
> mike
>
>
>
> At 03:07 PM 9/17/2004, you wrote:
>> Hi Mike,
>>
>> Hmmm, I saw this number on the web page you pointed two earlier:
>> http://home.fuse.net/engineering/Chimes.htm
>> (bookmarked, thanks)
>>
>> Any idea where that number comes from? Even fractions like 1/4 (25%)  
>> makes intuitive sense the way I understand the physics of standing  
>> waves. I poked around but didn't find anything supporting the 22.42%  
>> number?
>>
>> any ideas?
>>
>> Erik
>>
>> On Sep 17, 2004, at 9:01 AM, Mike Linn wrote:
>>
>>>
>>> The nodal points are actually 22.42 % from either end
>>>
>>>
>>>
>>> At 09:01 AM 9/17/2004, you wrote:
>>>> Yeah uh, ok,  but since the length of tube for a chime has to be  
>>>> some integral component of the wave , where are you sugesting to  
>>>> make the attachment ( as a fraction of the length)
>>>>
>>>> Maybe I am missing it and you have told us that, and I am just too  
>>>> dense this morning?
>>>>
>>>>
>>>> Charles
>>>>
>>>>
>>>> Bill Alleman wrote:
>>>>
>>>>> Larry and Pat Brown wrote on 9/17/2004, 5:04 AM:
>>>>>
>>>>> > If I remember correctly from making some wind chimes the  
>>>>> attachment
>>>>> > point is about 1/4 down the tube
>>>>>
>>>>> A half-wave, like a jumprope, doesn't get you any useable nodes.  
>>>>> One full wave (an octave) would be end to end, with a node at the  
>>>>> center. Then 1.5 waves (like a triangle) divides in thirds. The  
>>>>> next harmonic, 2 full waves, would have nodes at the 1/4s and 1/2.  
>>>>> Etcetera. The length, from attachment point to ends, should be an  
>>>>> integral number of half-waves, and I believe that the lower the  
>>>>> harmonic of choice, the better the effect. Like the guitar  
>>>>> technique Yes used in Roundabout...
>>>>
>>>>
>>>>            Mike Linn
>>>>      Artist Blacksmith
>>>>          McCalla, AL
>>>>        AFC Webmaster
>>>> http://afc.abana-chapter.com
>>>>
>>>>
>>>> "Don't worry Chief, I can stand the torture if they can stand the  
>>>> screaming."
>>>>                                              - Maxwell Smart,  
>>>> Secret Agent 86
>>>>
>>>>
>>>> ____________________________________________________________________ 
>>>> __
>>>>
>>>>
>>>>
>>>
>>>
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>
>
>            Mike Linn
>      Artist Blacksmith
>          McCalla, AL
>        AFC Webmaster
> http://afc.abana-chapter.com
>
>
> "Don't worry Chief, I can stand the torture if they can stand the  
> screaming."
>                                              - Maxwell Smart, Secret  
> Agent 86
>
>
> ______________________________________________________________________
>
>
>
>
>
>
> _______________________________________________
> Manage membership or unsubscribe at:
> http://mailman.qth.net/mailman/listinfo/theforge
> theforge mail list group photo site is
> http://www.photoaccess.com
> Login:  blacksmithblacksmith at hotmail.com
> password:  anvil
> ___________
>
>