<div>Yes that drawing is true if you are measureing the actual distance moved of the the arcs but we are talking weight and force not key dip and hammer travel. That action ratio is only good for distance. For weight or force, the effort is applied at the wippen cushion and transmitted to the jack pin. The jack is not a lever so the force at the top of the jack is equal to the force at the center pin. Correct me if I'm wrong but then I think I can move the jack back and forth at the knuckle, rotating it slightly about the center pin, and there is no significant change in force UNLESS you get the parts too far out of alignment. </div> <div>You need to look at what you are trying to acomplish. As you can see from the drawing that moving the wippen rail back will increase the length of the arc produced at the jack/knuckle and also decreases the length of the arc of the the corresponding effort arm. Therefore these two movements offset the distance changes of the the arcs and you see almost no change of measurement of hammer travel. Yes you are right. </div> <div>However the force transmitted did change and that is what you want. A lighter perception of the weight.</div> <div> </div> <div>Keith Roberts</div> <div><br><br> </div> <div><span class="gmail_quote">On 10/21/07, <b class="gmail_sendername">Jon Page</b> <<a href="mailto:jonpage@comcast.net">jonpage@comcast.net</a>> wrote:</span> <blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"> <div> <blockquote type="cite"><font face="Arial" color="#000000">I'm sorry but the resistance arm of the wippen is to the jack center pin.</font></blockquote> <div><br> </div> <div>Then YOU tell these guys that they're wrong...   (pdf attached)</div> <div><br> </div> <div>I have moved many a wippen rail and not had a minimal difference</div> <div>in touchweight or friction. But move the stack by the same amount and</div> <div>you'll notice a difference.  Moving the rail aligns the centers, moving the stack</div> <div>alters the Wippen Ratio. Moving the capstan alters KR and Wippen Ratio.</div> <div>So when relocating the capstans is not viable, look to the stack.</div> <div><br> </div> <div>I offered this option since we were speculating (lacking more info) on treatment</div> <div>of these actions.  When regulation or mass alteration does not accomplish</div> <div>your goal then look a little further.</div> <div><br> </div> <div>One sign might be shanks which are not centered over their rest cushions or wips</div> <div>in the bass and low tenor. Once the stack is moved (usually back) the realignment</div> <div>of the hammers to the strings also places the shanks more centered on the rest felt.</div> <div><br> </div> <div>To me it's just another overlooked aspect.</div><pre>-- </pre> <div><br>Regards,<br><br>Jon Page</div></div><br clear="all"></blockquote></div><br>