When I replaced the balance rail holes ala Spurlock, I drilled them slightly smaller the first pass and they were tight, really close. I took a 1/8" chainsaw file that mics at .130 to .135 on the cutting surface and it was tight so I inserted the file in the hole and rotated 1 turn counterclockwise and removed. (I had to make a handle). They were perfect on the new pins. Lucky me. So I ground off the back and sides of one of those files till I could taper the hole until the key rocked nicely and leave the bottom untouched. And when I checked them 2 years later they are still perfect. Keith Roberts On 7/26/07, Fred Sturm <fssturm at unm.edu> wrote: > > On Jul 26, 2007, at 11:46 AM, Jim Busby wrote: > > Fred, > > One difference/question I have is - isn't it easier to insert the proper > sizing cauls, then turn the set upside down and insert the BR pins (the > cauls won't let the pins fall through), then add sizing fluid? After they > dry, ream the mortise so the "foot" of the hole is the exact thickness. > > Takes a long time to insert those balance pins in each hole, and then pull > them out later (I don't have a bunch of student helpers, so a few seconds > here and there on each little procedure add up). I'm "reaming" with a drill > bit, which doesn't remove as much wood as a real reamer, and maybe leaves a > bit of "uncut splinters" (we're talking fairly microscopic) to hold glue if > I need to size later. That's my reasoning, anyway. And I think it leaves a > more stable condition than just putting in BR pins and letting the wood > conform to them, if your holes are too small to begin with. I'm closer to > having the right amount of wood (in this dimension, not to be confused with > the reaming you are talking about above). Making the hole exactly the size > of the pin will require a bit of easing. So I use one sizing caul, which is > heated. The heat increases the size of the balance pin in the caul from > .146" to .147", and the heat helps size the wood - make the size relatively > permanent. It puts the hole .001" larger than the pin, very nicely and > consistently. (Glue-sizing to make the hole smaller where needed is a > separate part of the procedure, done only to holes that are too large). > > Replace them on the Keyframe to check BR fit and fix pulley keys. > > That's a lot of time and work. I like to leave the keys in the clamp, and > bring the balance pin to the key. I can feel that pin going into the hole > very precisely, and also feel if there is any play in any direction.. > > Many times pulley keys are no longer an issue with the glue sizing > formula. BTW I use a much diluted (12/1 or so) Elmer's glue for sizing. Ron > N. tells me that this is the only place on a piano where he uses that glue. > (Thanks Ron) There is no sound, click, etc. with Elmer's glue as there is > with PVCE, Hot Hide, and or other glues. > > > > Baldassin taught me to add this extra step (it really doesn't take long) > of placing the keys back on the frame BEFORE the bushings are in so that you > can work the BR holes w/o "false readings" from overly tight new bushings. > It takes about 10 – 15 minutes longer but the total focus on the BR hole > pays big dividends, IMO. Here is when I deal with the pulley keys because > now you're sure of which ones weren't fixed by the glue sizing. > > Rick B is certainly correct in wanting to separate bottom hole from > bushings, so one doesn't mask the other. I think I do it with a lot less > time and effort. Putting a loose pin into the hole removes the factor of the > weight of the key. All that lead can mask a lot of problems. > > Anyway, just a bit more to consider for your book... Who knows? > Marriott's success, he said, was to "write out every tiny process and revise > it in writing until nothing more could be perfected, then get all your > employees to do it THAT way." > > I don't like having employees other than myself. That's one reason I am in > this business <G>. > > (I vote for you to write that book, sometime before your beard is > entirely gray?? You and Ron. Oh well, Ron…)) > > I don't think there's much chance of me compiling and writing in book > form. But if anyone else wants to do that, and make use of what I have > posted from time to time, that would be fine with me. Have at it with my > compliments. > > High regards, > > Jim > > Regards, > > Fred > -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/20070726/285bf1d1/attachment.html
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