Mark Cramer wrote: >I've run into this more frequently with Yamaha actions, Otto. > >With rep.springs set; "mild," the jack will not fully return during a lever >height "wink" test. > >To clarify we're talking about the same thing; the spring setting easily >passes the "smooth/immediate rise out of check" test, however, the rep.lever >can be raised 3 or 4 mm (1/8" plus) above, and the jack will still not >return fully under the knuckle, when released slowly. > >I don't like this situation either, but in such cases resort to setting rep. >lever height by spec. rather than feel (via the jack tender), and trust all >works as it should during actual playing conditions. > >So what actually causes this? > > > Mark... a few thoughts... If you are lowering the rep-lever spring tension then sometimes you need to back off just a rat tails hair on your jack top height to keep the jack capable of zipping back under the knuckle. The thing is on actions with a single spring for both the jack return and rep-lever what you do to one you do to both. So if you lower rep-spring strength then you have two factors that move against the jack getting back under the knuckle as quickly as you might like. First, the lever itself wont support quite the same weight which increases the <<bearing>> on the lever by the knuckle. On a borderline adjustment this can hang the jack top up on the knuckle. Secondly the jack itself isnt pulled back as strong as before. A couple obvioius tricks is to pin the replever tight and jack loose so that you can get away with a higher rep lever spring strength to begin with. You can aslo pin the hammershanks as tight as you can get away with to maximize the effect. The backside here tho is that you can easily end up with a realllllly strong back pull on jack which in turn can really bang into the stop pad. My best advise is to not dink around too awfully much with standard pinnings, and make sure you have decent friction values all the way around. Make especially sure of your knuckle condition. Teflon powder applied with a used number 80 hammer works wonders, but if the knuckles are worn and malformed then you are bound to have some troubles. If you must have a really low rep-lever spring strength... then be ready to accept reduced repetition. That said.... under usual play many techs are suprised to find out just how low strength you can easily get away with while maintaining more then adequate playing repetition. Hope this helps a bit... tho no doubt you've thought of much of this already. :) Cheers RicB
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