Thanks, David. The articles you may be thinking about were by Bob Hoff, Action Elevations, June - September of 2000. I keep rereading them. I may check with Wally Brooks next time because I don't think the Renner kit had any other choices that had a larger roller and yet still had the other necessary dimensions. Cheerios, Bob Hull --- David Love <davidlovepianos@comcast.net> wrote: > There was an excellent article in the journal a few > years back on action > elevations. Can't even remember who wrote it now, > but it might be worth > reading at this point. Someone with a better memory > for these things > will offer the author and issue I'm sure. My > general approach in these > situations is to kind of start over and try various > combinations of > parts to see what gives me the best combination of > regulation and > leverage. I try and at least get the convergence > line from the balance > rail to the wippen center on target with the > capstan/wippen cushion > contact point on the line when the key is halfway > through it's travel. > If you are using the wippen with the various cushion > heights, you can > play around until you get the one that works. You > can alter the spread > as needed to get jack alignment with the knuckle > and, sometimes, > clearance between the hammer flange rail and the > balancier. I don't > remember the configuration on a Weber that well > without looking at one. > If you are replacing shanks and can't find the right > knuckle center > dimension from Renner, check Abel shanks from Brooks > Limited. He has > some configurations that Renner doesn't. At this > point, I think you > just have to play around with samples. Double check > the bore distance > to be sure that you are using a correctly bored > hammer for your trials. > > > > David Love > davidlovepianos@comcast.net > > -----Original Message----- > From: pianotech-bounces@ptg.org > [mailto:pianotech-bounces@ptg.org] On > Behalf Of Bob Hull > Sent: Saturday, March 19, 2005 2:57 PM > To: Pianotech > Subject: RE: low drop screw symptom > > David, > > Your comments are appreciated. Here's my answer to > your questions. > > --- David Love <davidlovepianos@comcast.net> wrote: > > What kind of piano is this? > > It is a 5'6" Weber which was rebuilt by someone > else > only 6 years ago but the pinblock was very poorly > fit, > the wippens were not replaced and cheap parts were > poorly used. Now the wippens have failed (silk cord > type)so we decided to start over and hopefully do > things better. > > > If you have to lower the drop screw it may > indicate > > that the bore > > distance on the hammers is too long. Lowering the > > let-off button is > > usually accompanied by the lowering of the drop > > screw and vice versa. > > Andre said something about capstans having to be > lowered and this is true, I am having to lower the > capstans on the samples to set the hammer blow dist. > > > The shank relationship to the knuckle can be > altered > > by changing the > > spread, shimming out the whippen flanges or the > > flange rail. You will > > have to determine the appropriate spread by trial > > and error probably. > > > > The harder feel at let-off of the new wippen may > be > > because the surface > > area of the top of the jack is greater on the new > > one than the old one. > > What condition are the knuckles in? You may want > to > > consider changing > > the knuckles if you are not changing the shanks. > > I am replacing the shanks but now I thinking about > trying a different shank with a bigger knuckle if I > can find the same dimension from the center pin. I > hate not having the original parts to reference. > > > I would measure and calculate just how much you > need > > to lower the plate > > to get the bearing you want and on which side you > > have the problem. > > Also, measure the crown. If you are lowering the > > plate onto a board > > which is already flat or worse... Lowering the > > plate at the outside > > perimeter is not likely to change the hammer bore > > dimension. Lowering > > the plate at the block might, it depends on how > much > > you are lowering > > it. Are you installing a new pinblock? > > I have already put in a new pinblock. The board was > repaired and coated with System 3 epoxy. > I lowered the plate as much as I dared, just enough > to > get some downbearing but not push the board to hard > because of its age. I did have to lower it also at > the block because the thread would contact the back > of > the bridge before the front as it came from the > agraffe. > > > David Love > > davidlovepianos@comcast.net > > > > -----Original Message----- > > From: pianotech-bounces@ptg.org > > [mailto:pianotech-bounces@ptg.org] On > > Behalf Of Bob Hull > > Sent: Saturday, March 19, 2005 7:23 AM > > To: pianotech@ptg.org > > Subject: low drop screw symptom > > > > Hello List, > > > > On a rebuild for a small but good quality grand I > am > > replacing all of the action parts and having some > > doubts about the action configuration. As I > > regulate samples the drop screw has to be lowered > > almost as far as it will go. > > > > Another relationship that appears to be off is the > > jack to hammershank relationship which is not > > perpendicular but rather it is more toward the B- > > side > > (Bob Hoff terminology). How can I change this? > > > > The new (Renner) wippen with the closest match to > > the > > old wippen is the one with the added heel. The > old > > jack tender/toe seemed to interface better with > the > > tilted let off rail than the new wippen does. The > > new > > one gives a harder feeling ledge before let off. > > I don't like the way that feels. > > > > I realize that more information may be necessary > > and > > I can supply it if asked. One other thing I will > > add > > is that I had to lower the plate/string plane as > > much > > as I dared to get some downbearing. I am > adjusting > > the hammer bore because of this. > > > > So to restate my question: What is indicated > about > > an > > action geometry when drop screws must be lowered > so > > far in order to attain suitable drop? > > I would appreciate your comments. > > > > Bob Hull > > > > > > > > > > __________________________________________________ > > Do You Yahoo!? > > Tired of spam? Yahoo! Mail has the best spam > > protection around > > http://mail.yahoo.com > > _______________________________________________ > > pianotech list info: > > https://www.moypiano.com/resources/#archives > > > > > === message truncated === __________________________________ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/
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