Agree, if you increase dip, work stays the same in my example. I was assuming constant key dip, or any constant movement - say 1mm. With VC you don't have to increase dip. Therefore the work appears to decrease. But that's impossible since same work is being done to lift wippen/hammer (even more to lift magnets). Where does the extra work/energy come from? (Maybe if I ask enough times in enough ways...) -Mark ----- Original Message ----- From: "Bill Ballard" <yardbird@vermontel.net> To: "Pianotech" <pianotech@ptg.org> Sent: Saturday, June 21, 2003 3:54 PM Subject: Re: Virtual Capstan > At 1:52 PM -0400 6/21/03, Mark Davidson wrote: > >I agree that moving some of the upward force closer to the balance > >rail increases leverage. But consider for a moment the example of > >moving a regular capstan toward the balance rail. Downward force > >required to move the key is decreased. Work at front of key = force > >* distance, which is less because force is less. However the wippen > >and hammer also do not move as far, so the work at the back of the > >key is ALSO less. The changes balance out. > > Keep in mind that when you move a regular capstan towards the balance > rail, what's being changed is the leverage of the key. Actually the > formula should be, work done at the front of the key should equal the > work done at the capstan (less amount of energy lost to friction), > for any particular set-up. Because of the leverage change in moving > the cap closer to the fulcrum, the capstan's motion is now decreased > in relationship to the key front. > > Force at the front of the key needed to overcome the top action > weight (BW-FW) is reduced, but the other consequence is that the > front of the key has to move further. In this situation as well, work > done at the front will equal work done at the capstan. > > What balances out is that you've bought the ability to move a heavier > weight, at the expense of how far you can move it. > > >With your idea, however, the wippen and hammer move the SAME > >distance with or without magnets (same amount of work at back of > >key) but with different amounts of work at the front of the key. > >This is actually a huge advantage because you do not have to > >re-regulate dip/blow etc. > > The only reason to re-regulate dip/blow would be if you'd hanged the > mechanical leverage ratio. Because the capstan is still in place to > govern the rotation of parts, and because it hasn't moved, the > leverage ratio is unchanged. In this respect, springs and magnets > offer the same thing. Let's hope that Antares isn't being too hasty > in pulling out the springs out of his own action. > > Bill Ballard RPT > NH Chapter, P.T.G. > > "Talking about music is like dancing about architecture" > ...........Steve Martin > +++++++++++++++++++++ > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives
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