<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:st1="urn:schemas-microsoft-com:office:smarttags" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv=Content-Type content="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 11 (filtered medium)"> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceType"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceName"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PersonName"/>  <style>  </style> </head> <body lang=EN-US link=blue vlink=blue style='word-wrap: break-word;-khtml-nbsp-mode: space; -khtml-line-break: after-white-space'> <div class=Section1> Fred,<o:p></o:p> <o:p> </o:p> 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. Replace them on the Keyframe to check BR fit and fix pulley keys. 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.<o:p></o:p> <o:p> </o:p> 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.<o:p></o:p> <o:p> </o:p> 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.”<o:p></o:p> <o:p> </o:p> (I vote for you to write that book, sometime before your beard is entirely gray?? You and Ron. Oh well, Ron…))<o:p></o:p> <o:p> </o:p> High regards,<o:p></o:p> Jim<o:p></o:p> <o:p> </o:p> <div> <div class=MsoNormal align=center style='text-align:center'> <hr size=2 width="100%" align=center tabindex=-1> </div> From: caut-bounces@ptg.org [mailto:caut-bounces@ptg.org] On Behalf Of Fred Sturm Sent: Thursday, July 26, 2007 8:00 AM To: <st1:PersonName w:st="on">College and University Technicians</st1:PersonName> Subject: [CAUT] Key bottoms (was Re: key-easing pliers?)<o:p></o:p> </div> <o:p> </o:p> <div> <div> On Jul 25, 2007, at 11:03 AM, Mark Cramer wrote:<o:p></o:p> </div> <o:p></o:p> BTW, Bill's system is absolutely beautiful! I think we started with the<o:p></o:p> cauls in 95 (?) then added the heated-broach system (thank-you Master<o:p></o:p> Wolfenden!) from Pianotek, and finally the mortise-sizing cauls, whenever<o:p></o:p> they became available.<o:p></o:p> <o:p> </o:p> With the control over key-pin, mortice and cloth sizing, so little variable<o:p></o:p> remains. We record the cloth and heating broach size (as many of you do)<o:p></o:p> right on the key-board and in our records.<o:p></o:p> </div> <o:p> </o:p> <div> I couldn't agree with Mark more on how much better work is possible with current techniques, tools and materials. The fly in the ointment for me has been bottom holes. I have wished for years I could finish the bushing job, take the keys from the clamps, put them on the pins and be done (essentially, with very, very minor tweaking). But I find bottom holes slow this considerably, needing custom work on most keys after steaming out bushings. I've tried a lot of ideas, and none were quite satisfactory. But I have finally come up with a system I like, which takes me under 20 minutes, keys in clamps.<o:p></o:p> </div> <div> <o:p> </o:p> </div> <div> 1) Check for holes that are too large, for sizing. Keys laid balance holes up, take a loose balance pin and insert in each hole. If a hole is loose enough the pin wants to fall in, wiggle the pin in the hole. If there is any chatter, chalk it and move on. Size the chalked holes with your favorite method.<o:p></o:p> </div> <div> 2) Remove excess wood where present. I know, lots of "experts" have told us for years we should "never remove wood" here. They are wrong. We should never remove _too much_ wood here. Eric Shandall is now teaching use of parallel reamers for the purpose of easing too tight balance holes, in Steinway factory seminars. He uses .1470, .1475, and .1480 I believe, usually finding .1475 best. These are available on the web for maybe $10 each.<o:p></o:p> </div> <div>             I decided there was too much danger of taking too much wood using a reamer, and anyway I don't need yet more tools to keep track of, so I decided to try a drill bit instead. #26, from a #1 - #60 set, is .147. (If you feel paranoid about humidity swings and whatnot, use #27, .144". And, obviously, if the keypins are a different size, change accordingly). My technique is to push the bit into the hole by hand (no twisting) and pull back out. If the hole is particularly small, I repeat once or twice. To make it easier, I attach a stop collar to the bit (a pin vise would work). With a new, sharp bit, the flutes will cut pretty well. I find I mostly remove some splinters and some black sticky residue.<o:p></o:p> </div> <div> 3) Heat size, using a home made caul in the keybushing iron setup (heat controlled soldering iron). Short piece of 1/4" brass, drill a hole with #27 bit (.144"), pound in a balance pin cut in half. Use it like ironing keybushings: about the same temperature and same time. No more than 1.5 seconds per hole. (The idea comes from Brian DeTar, who used something similar for sizing damper guide bushings. I have three similar things for that purpose, with #6, #7, and #8 bridge pins as the "irons. Works great!)<o:p></o:p> </div> <div> 4) Even up key bottom thickness, using a balance hole reamer (idea of doing the whole set, as a common procedure, courtesy of Roger Jolly). Keys are held vertical, so that you can get at both sides at once. Insert through the top of the key, gauge how much should protrude through the bottom hole by eye and by feel (I guess you could make a stop gauge of some sort if you wanted to). Go through the whole set doing the same to each key. Sometimes this is a formality, sometimes it was really needed. I guess this step might go earlier in the process, before you even glue in key bushings, so chips can be easily knocked out. <o:p></o:p> </div> <div> 5) Ease with balance hole easer, to make holes tapered. First feel holes with a loose balance pin. THey should be pretty consistent, with a little friction resistance. Find one with fairly high resistance. Insert the easer from the other side and ease. Feel with the pin. When you have it so that there is next to no friction, and no chatter at all, remember the feel and distance the easer is protruding through the bottom. Match that for every key. At first, you might check every key or so with a pin, until you feel confident. But this can be done quite precisely and easily, now that all holes are so consistent. If you like, make a stop gauge for more control and consistency, if you don't trust the feel of your hands and your eyesight.<o:p></o:p> </div> <div>             Now take the keys out of the clamps and install. <st1:City w:st="on"><st1:place w:st="on">Eureka</st1:place></st1:City>! It works! Perfection at last! <o:p></o:p> </div> <div>             Next time for this set of keys, steps 2 and 4 can be omitted.<o:p></o:p> </div> <div> <o:p> </o:p> <div> <div> Regards,<o:p></o:p> </div> <div> Fred Sturm<o:p></o:p> </div> <div> <st1:place w:st="on"><st1:PlaceType w:st="on">University</st1:PlaceType> of <st1:PlaceName w:st="on">New Mexico</st1:PlaceName></st1:place><o:p></o:p> </div> <div> <a href="mailto:fssturm@unm.edu">fssturm@unm.edu</a><o:p></o:p> </div> <div> <o:p> </o:p> </div> </div> <o:p> </o:p> </div> <div> <o:p> </o:p> </div> <div> <o:p> </o:p> </div> </div> </body> </html>