Thanks for the feedback, Don. I wonder how many keystrokes an average 18 hour a day practice room piano gets? Hard to guess. Humidity drop of 40% plus might be the biggest factor. I do most of my pinning in the summer, when it's highest. I'd love to use a long piece of music wire for burnishing, but where am I going to get one of proper diameter? What I keep in stock goes only to #21, which is .047. I could buy larger sizes, but Pianotek shows 23, 24 and 25 as being .051, .055, and .059 (and doesn't list half sizes. I don't have my Schaff catalogue handy). And anyway, I hate to buy a pound for a couple feet of wire. Is there another source? Yes, I guess those bad broaches did probably come from APSCO. I have found them usable with modification - don't ever let the saw teeth near the felt, just made my own rough area farther down. But mostly I use my other set. I like the handles provided just fine, but they're much too bulky for the tool case. I'm glad to hear that up to .055 is available now. I guess it's been a quite a few years since I bothered to check. Regards, Fred Sturm University of New Mexico --On Friday, October 3, 2003 7:56 AM -0700 Don Mannino <dmannino@kawaius.com> wrote: > Hey Fred (and list), > > I sort of figured you were putting more friction there in compensation > for conditions. They should not loosen up as much as you said, though - > an average of .5 gram resistance drop in hammer flanges after 20,000 > keystrokes is what I found when testing the process. If the cloth isn't > very good that could make it worse, or if the broaches are too rough. > > On the next repinning job you do on parts that are not too old, try > using only a 2 foot long stretch of music wire to burnish only. Just > sharpen an end, then drag each part over the long wire. If you are not > having to change the pin size up more than .001, then this burnishing > can be enough to create a firm and stable center with low friction (2 - > 4 grams), even under heavy use. > > The rough broaches you received were not made correctly - they sound > like the ones APSCO was selling, which were wrong and did not follow my > design. You should not continue to use them - they should be trashed. > > Schaff is making the sets with 8 broaches now, the smallest is .048 and > the larges .055. These have been available for a couple of years now. > Be sure to run the broach onto the part all the way to the handle, so > that the rough area simply scuffs by the bushing as you run it on and > off. > > I agree, the handles don't need to be as big as Schaff makes them, but I > sort of like the shape of them. > > Don > >> -----Original Message----- >> From: Fred Sturm [mailto:fssturm@unm.edu] >> Sent: Friday, October 03, 2003 6:40 AM >> To: College and University Technicians >> Subject: RE: Steinway "pinning" dilemma >> >> >> Hi Don, >> I agree that for most purposes, 8 grams of friction in >> a shank would be >> excessive. I should have qualified the number: >> 1) Only on high use grands >> 2) with heavy-ish hammers >> 3) bass to tenor area >> 4) when done during high end of humidity cycle >> 5) in conjunction with application of Protek >> 6) with a cross check of minimum three swings >> I have found a fairly rapid drop in friction after >> re-pinning, somewhat >> similar to drop in torque when stringing, where after two to >> three months >> (granted, of heavy use, and possibly drop in humidity), >> friction will drop >> by at least a couple grams, and number of swings will >> increase from three >> to five, from four to seven, or so. In a sense, what I am doing is >> "floating" frictional parameters - making it too tight to >> begin with so it >> will be right longer. And removing as little felt as possible >> to preserve >> the bushings as long as possible. I typically use 3 to 5 >> grams for home or >> low use. And maybe my dry climate and low air pollution has a >> big effect on >> efficacy of these parameters. >> I do use a commonly available set of tools known as >> "Mannino broaches" >> (hmmm, maybe some relative of yours, Don <g>), and rough up >> the felt as >> little as possible, in conjunction with solid burnishing. >> BTW, I have found >> those broaches can vary quite a bit. I bought two sets over >> time, one for >> home, one for school, and the first set was great. The second >> had extreme >> roughness in the cuttin area - real deep spirals. Not hard to >> get around. I >> just made my own rough spots a little down the wire, and >> don't get into the >> pre-made rough. But it may be something to watch for. Also, >> the same second >> set had nasty burrs by the sharpened end, so that it would >> cut felt while >> being inserted in the bushing (easily removed with a file or >> sandpaper). >> As long as I'm on the subject, I like to replace the >> rather bulky handles >> with home made ones out of 1/8" dowel. This is plenty of >> handle for the >> purpose, and allows me to carry the set with me in a very >> compact kit made >> of a small square of firm corrugated cardboard - just press >> the broaches >> through the corrugations (don't insert in the corrugation >> holes, go cross >> wise and puncture each corugation). The square goes with my nice new >> pinning tool by Mike Calahan (boy is it nice to have zero >> wobble/side play. >> Definitely my favorite purchase from the Dallas convention) >> and pin nippers >> into a small pouch made of mackintosh. >> One more thought: I sure wish there were two more sizes >> in these broach >> kits - up to 22 1/2 centerpin (.055). And I sure wish action >> makers would >> revert to starting off with 19 centerpins, instead of 20.5 or >> so. Regards, Fred Sturm University of New Mexico > _______________________________________________ > caut list info: https://www.moypiano.com/resources/#archives
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