[CAUT] Moving capstans

Alan McCoy amccoy@mail.ewu.edu
Wed, 20 Oct 2004 11:25:53 -0700


Thanks everyone for the ideas. Looks like it's time to experiment. I
actually have Nick's geometry software but haven't used it for awhile
because I like Stanwood's methods. Using weight instead of distance seems
more direct and easier (and probably more accurate).

Alan


> From: Richard Brekne <Richard.Brekne@grieg.uib.no>
> Reply-To: "College and University Technicians <caut@ptg.org>" <caut@ptg.org>
> Date: Wed, 20 Oct 2004 09:01:48 +0100
> To: <ed440@mindspring.com>, "College and University Technicians
> <caut@ptg.org>" <caut@ptg.org>
> Subject: Re: [CAUT] Moving capstans
> 
> Nicks program does not yeild the same BW result that Stanwoods formula
> does. It is based on Pfieffers formula  unless I am mistaken and results
> in a different ratio quantity. It can be used as a reference for sure...
> but it will not yeild the Balance Weight Ratio as it does not take into
> consideration any angles of any of the parts in any given position. It
> simply breaks the levers down into three individual ratios as free
> standing levers, and multiplies the results together.
> 
> It can give you a general idea, but remember if you move either the
> knuckle or the capstan.. you are essentially really moving the jacktop
> and whippen cushion respectively as well.
> 
> Cheers
> RicB
> 
> Ed Sutton wrote:
> 
>> Alan-
>> 
>> Nick Gravagne has a program for sale to do what you want.  He offers 2
>> weeks' free trial. <http://home.att.net/~nickware/action.htm>
>> 
>> I haven't tried it, but it looks good.
>> 
>> Some pianos may work better with different capstan lines for naturals and
>> accidentals. 
>> 
>> In the end you will have to do practical trials anyway. I have a capstan on
>> a block of wood on the end of a stiff wire.  I can fish quickly to get some
>> rough ideas of what will work.
>> 
>> Also, some light go bars over the bench make it faster to pull and replace
>> the stack
>> 
>> Please let us know how it goes if you try Nick's program.
>> 
>> Ed Sutton
>> 
>> 
>>  
>> 
>>> [Original Message]
>>> From: Alan McCoy <amccoy@mail.ewu.edu>
>>> To: College and University Technicians <caut@ptg.org <caut@ptg.org>
>>> Date: 10/19/2004 5:58:21 PM
>>> Subject: Re: [CAUT] Moving capstans
>>> 
>>> Hi Chris,
>>> 
>>> I know the formula for R, etc. I could also just physically move a capstan
>>> and recalculate. The question though is how to predict the change in BW
>>> resulting from moving a capstan or knuckle, before actually moving it (as
>>> per the analysis sheet).
>>> 
>>> Alan
>>> 
>>> 
>>>    
>>> 
>>>> From: Chris Solliday <solliday@ptd.net>
>>>> Reply-To: "College and University Technicians <caut@ptg.org>"
>>>>      
>>>> 
>> <caut@ptg.org>
>>  
>> 
>>>> Date: Tue, 19 Oct 2004 16:43:31 -0400
>>>> To: "College and University Technicians <caut@ptg.org>" <caut@ptg.org>
>>>> Subject: Re: [CAUT] Moving capstans
>>>> 
>>>> SR= BW+FW-(KRxWW) divided by SW the rest is simple math.
>>>> ----- Original Message -----
>>>> From: "Alan McCoy" <amccoy@mail.ewu.edu>
>>>> To: "CAUTlist" <caut@ptg.org>
>>>> Sent: Tuesday, October 19, 2004 4:28 PM
>>>> Subject: [CAUT] Moving capstans
>>>> 
>>>> 
>>>>      
>>>> 
>>>>> Hi Folks,
>>>>> 
>>>>> I'd like to pick some of your brains about a problem action. I thought
>>>>>        
>>>>> 
>> it
>>  
>> 
>>>>> might help the discussion to include my spreadsheet, but the list
>>>>> administrator thought it better to separate the attachment. If you want
>>>>>        
>>>>> 
>>>> to,
>>>>      
>>>> 
>>>>> please go to http://www.ptg.org:1406/files/20041019125312.xls for the
>>>>> worksheet.
>>>>> 
>>>>> Is there some way to calculate how much BW will change when moving
>>>>>        
>>>>> 
>> either
>>  
>> 
>>>>> the knuckle or the capstan? Or does anyone have enough experience/data
>>>>>        
>>>>> 
>> for
>>  
>> 
>>>> a
>>>>      
>>>> 
>>>>> rule of thumb for this calculation?
>>>>> 
>>>>> Comments?
>>>>> 
>>>>> Thanks.
>>>>> 
>>>>> 
>>>>> -- Alan McCoy, RPT
>>>>> Piano Technician
>>>>> 
>>>>> Eastern Washington University
>>>>> 119 Music Bldg
>>>>> Cheney, WA 99004
>>>>> 
>>>>> (509) 359-4627
>>>>> amccoy@mail.ewu.edu
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> _______________________________________________
>>>>> caut list info: https://www.moypiano.com/resources/#archives
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>>>>> 
>>>>>        
>>>>> 
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>> 
>> 
>> 
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>> 
> 
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