Jim, Thanks for your detailed and useful response to my query. I will certainly bear knuckles in mind when assessing the situation. You suggestion on diagnostic procedure is also particularly well-taken. I'm going to respecfully disagree with one statement you made, quoted below. I believe the general consensus at this point is that wipp assist springs _should_ be used in a controlled manner to adjust touch weight. Not individually, varying from note to note, but definitely consistently throughout the action. I believe the manfacturers and their representatives would bear me out - that the springs should be adjusted to reduce touch weight by somewhere between 10 and 20 grams (IOW, keys are leaded to produce, say, 70 grams downweight - friction being controlled so that we are really dealing with a 50 to 60 balance weight - and then springs are adjusted to produce, say, 55 gm). This is certainly what the Knabe and Sohmer technical consultant (otherwise known as Roger Jolly, on the payroll of Samick <g>) would say. I believe Don Mannino would say more or less the same on behalf of Kawai. And, at the same time, there is a large contingent of technicians who retrofit using wipps with assist springs, for the purpose of being able to control hammer weights and reduce the inertial problems associated with too much lead in the keys. Ron Overs uses such a wippen, with the very handy addition of an adjustment screw for accurate control, on his action. Bob Marinelli recently added a wippen with a similar adjustment screw to his parts assortment (Pianotek). Certainly one shouldn't go into a piano with wipp springs and use them for touch control in a helter skelter manner. But if one evens out the frictional component, and adjusts key leading, with springs disengaged, at 10 to 20 grams heavier than target as a foundation (meaning one chosen figure in the range between 10 and 20), then adjusting spring tension to get final downweight is a very proper and useful procedure, IMHO. Regards, Fred Sturm University of New Mexico Quoting Jim Harvey <harvey@greenwood.net>: > Hi Fred, > >snip< > Any touch weight changes via the auxiliary springs are not > only minimal, but coincidental. IOW, they were not intended to > provide > adjustable touch weight. There are two schools of thought on > regulating these springs: > 1. Sidecutters > 2. Assuming wippen flange centers are free, adjust auxiliary springs > so that wippen -just- follows, not pushes, the knuckle when a hammer > is manually lifted from rest position. >snip< > Regards, > Jim mailto:harvey@greenwood.net > > _______________________________________________ > caut list info: https://www.moypiano.com/resources/#archives >
This PTG archive page provided courtesy of Moy Piano Service, LLC