Hi Gregor, Ted's CAUT post of Oct 15/07 is quoted below. He was responding to a post from David Ilvedson, as noted. What I'm exploring here is new ground for me, and I'm trying to establish points of reference. Thanks for your interest! Floyd Gadd Gregor wrote: That´s what I was wondering about, too. And how do you do it? Do you dismount the whippen including the jack for measuring? Concerning the damper spring: 40 grams on which damper? Bass or treble? Gregor [CAUT] Upright geometry problem (Nordiska) Ted Sambell edward.sambell at sympatico.ca Mon Oct 15 13:25:30 MDT 2007 Several years ago I attended the Europiano convention in Germany, at which engineers from Schimmel dealt with this question. For the jacks, simply use a force gauge, placing the feeler on the jack heel and moving the jack forward with it. The recommended reading is 30 grams, not more. To check the damper springs, mount the action on the bench horizontally with the dampers uppermost and use the force gauge on the damper felt to press downwards about the distance of the damper lift. The optimum reading is 40 grams. The engineers said that increasing the spring strength above this does not improve damping efficiency. In my experience I have found that excessive spring strength also causes hammer bobbling. Ted Sambell >I know how to reduce or increase the tension it is getting it even that I'm >wondering about...some sort of gram gauge pulling on the damper? Maybe it >is simply trying to pull the spring towards you the same amount for each >damper? > > David Ilvedson, RPT
This PTG archive page provided courtesy of Moy Piano Service, LLC