Fred (and listserve members)~ Thanks for your excellent thoughts and suggestions. I too, am wondering how they strung these at the factory. It would be great to hear from anyone who knows. I think there might also be some confusion here because Wurlitzer apparently used two different configurations for these iron pinblocks. The one I am working on uses a machine screw with a relatively fine thread to hold the tuning pin in from the back (or underside on a grand), but you brought up a good point: there was also a design that used wedges, and a tuning pin that was split at the bottom to accept the wedge, which wedge could then be pounded in further to tighten the pin (which design I have also seen in my travels, but unfortunately don't have a picture of.) Here again is the picture of the system I have, in case you didn't see it (this, incidentally, is taken from Nalder's book, The Modern Piano. The photo, I'm pretty sure, is in the public domain.) (See photo link below if you are reading this from the archives) As you can see, it is impossible to remove the pins from the front (in an upright) or top (in a grand) of the plate web. The smaller diameter part of the hole, through which the pin emerges out the face of the plate web, is the same diameter as the shank of the tuning pin: it fits the pin snugly like a new tuning pin bushing (One distinct advantage: these pins really do not flagpole, at all! ). There is essentially no clearance between the pin and the hole, and, of course, the wedge or splayed part of the pin will not pass through this hole: that would defeat the purpose of the design. So the pins must be removed or inserted from the rear. But this precludes winding the coil on the pin in the normal fashion, with the pin out of the plate. The pin will not pass through the hole with the coil installed, because the hole is too small. So I see no alternative except to somehow string the piano with the pins installed. The alternatives seem to be, from the suggestions I have received from members of the listserve, to either wind the coil on a dummy pin and then transfer it to the pin in the piano, or to simply wind the coil on the preinstalled pins themselves. Clarence Zeches had an excellent suggestion about loosening the wedging screw somewhat to wind the coil, then tightening the screw afterward, as the pins are pretty tight with the screws snugged up; loosening the screws before giving the pin its three turns would lessen the possibility of breaking a pin, which would then require a visit to a machinist, who hopefully could make a new pin... (maybe I should check the feasibility of this before attempting the restringing...) Because the holding screws have a fairly fine thread, they take some time to screw in or out. It seems advantageous not to have to remove the pins or screws in the first place, but if the pins have been sprayed gold (as in someone regilding the plate with the pins and strings installed, as they did the one I am working on) then I may end up removing all the pins and cleaning or polishing them. In light of that, I am greatly appreciative of Norman Cantrell's suggestions about cleaning the pins and regilding the plate with the pins installed, using the Travis tuning pin cleaner system, and heat shrink tubing to mask the pins while regilding the plate. (Especially when I consider having to remove and install them all again...) Wolfenden, in The Art of Pianoforte Construction, in the chapter on "tuning and tuning appliances", comments that one of the problems encountered was the seizing of the pin due to rusting of the pin to the iron plate, under very humid conditions. I think Wurltizer attempted to circumvent this to a degree by plating the pins, and also by applying some kind of graphite grease to the pin before insertion. It seems to have worked - at least, I haven't found any pins on this piano that have rusted, or are seized. If all the parts hold up (if I don't break any pins or strip any screws) I think it will turn out well. The design seems to work well, and it's nice to be able to adjust the tuning pin torque so easily (just put a torque wrench on the pin and tighten or loosen the screw accordingly). It seems to be considerably easier to perform the screw adjustments in the grand, where you just have to have access to the action compartment (removing the action is really necessary, however, to access the screws on the underside of the plate). With an upright, it seems it would be more tedious, having to go around to the back of the piano to turn the screws.The main liabilities seem to be the tuning pins and the holding screws, for which there are no off-the-shelf replacements today (you may be very soon seeing a search inquiry on this listserve for salvage parts, however ;-). ) Barring the discovery of any additional restringing "shortcuts", or factory tricks, I think I am resigned that it may just take considerably longer than a normal restringing. Thanks so much for all your advice and tips so far. If anyone has any additional ideas or tips, they will be most appreciated. Kendall Ross Bean PianoFinders www.pianofinders.com <http://www.pianofinders.com/> e-mail: kenbean at pianofinders.com phone: (925) 676-3355 Connecting Pianos and People Fred Sturm wrote: I don't believe these pins will back out. The wedge in the bottom makes them a bit thicker at the bottom than the top. So I would just loosen enough to remove coils, clean up, set all the beckets in line with one another, and restring transferring coils to the existing pins. I have often puzzled about how they strung these in the factory (something to think about while tuning the one in my client base), and it has seemed to me that it would be pretty hard to come up with a way that didn't start by the pins installed in the web, plate reversed (something supporting the tops of the pins), then wedges pounded in, then plate turned upright and installed in the piano, then strings installed in some fashion (coiled in place, or coils transferred to them). I can't imagine a way of getting those wedges in efficiently with the plate in. I guess some form of long-necked plier to squeeze them in, maybe. But the idea of making a coil on the pin, putting it in the hole, and then adding the wedge, well, it just doesn't compute for me. I wish there was an old-timer around to ask. I've long been curious. Regards, Fred Sturm University of New Mexico <https://www.moypiano.com/resources/#archives> fssturm at unm.edu On Sep 12, 2008, at 6:08 PM, Clarence Zeches wrote: > Years ago I had an upright with these pins. I was going to restring > it until I realized what the system was. It was amazing that the > tuning pins were very tight. I think if you back out (down on a > grand) the screw a little to loosen the tuning pin then put the new > string in and do your normal wraps, then tighten the screw up again > it will work. The stringing would be like a normal string > replacement with the tuning pin already in the piano. I have no > idea to the amount of time to restring one. > > Clarence Zeches -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/20080913/42997d93/attachment-0001.html -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 49819 bytes Desc: not available Url : https://www.moypiano.com/ptg/caut.php/attachments/20080913/42997d93/attachment-0001.jpe
This PTG archive page provided courtesy of Moy Piano Service, LLC