<html> <head> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 10 (filtered)"> <style>  </style> </head> <body lang=EN-US link=blue vlink=purple> <div class=Section1> I have to agree with Keith here, at least as far as my overall understanding goes.  The three leverage points are hammer flange center to knuckle contact point on balancier (unchanged by wippen move); wippen center to capstan heal contact point (changed, in this case improved, by shimming out wippen flange), and key balance rail contact to capstan/wippen heal contact.  The overall leverage is a function of those three distances.   While friction may change depending on the degree of sliding, the balance weight, as we all know, will not.  Occam’s Razor, “one should not increase beyond what is necessary the entities to explain anything”.    I go back to my original assertion and what my own experience has demonstrated: shimming the wippen flange is just as effective as moving the stack and unless there are other compelling reasons to move the stack, as Jon cited in a previous post, I would recommend this as a more expeditious method of gaining a slight mechanical advantage.  Whether it creates a problem with jack alignment is something that once should consider prior to such an undertaking.  Personally, I’ve found that there is some leeway in this area.          <div> David Love davidlovepianos@comcast.net www.davidlovepianos.com </div> -----Original Message----- From: caut-bounces@ptg.org [mailto:caut-bounces@ptg.org] On Behalf Of Keith Roberts Sent: Thursday, October 25, 2007 4:02 AM To: College and University Technicians Subject: Re: [CAUT] Moving wippen rail   <div> The reason I disagree with the premise below is simple. We are looking at the wippen as a separate unit but we measure the change in output of the wippen as a function of the the entire action. Yes, the wippen power will increase as the jack approaches the line tangent to the RA but you are losing power at the other end as the force vector there diverges away from the tangent line of the shank EA. Therefore the change in jack position has absolutly NO effect on the resulant force. <GRIN> of course it has some but as you will see it doesn't change proportionally to the output of the system but changing the ratio of the wippen EA certainly does and is fairly accurately reflected by the drop in DW. </div> <div> Friction, HA! measure the friction and tell me there is a change. </div> <div>   </div> <div> Keith </div> <div>   </div> <div>   </div> <div> <blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt; margin-left:4.8pt;margin-right:0in'> So... really  I have to go with Jon here.  The change in apparent leverage is because of vector alignment. One also will experience a change in friction. Cheers RicB    I shimmed a rail out today and yes, the UW & DW dropped. I don't    attribute it to    improving wippen ratio but vector alignment.  If I kept moving the    rail back    I'm sure the numbers would degrade.    --    Regards,    Jon Page    LET'S GO RED SOX </blockquote> </div>   </div> </body> </html>