<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD><TITLE>Re: No Power Yamaha revisited (accurate bedding = adjust</TITLE> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <STYLE type=text/css>BLOCKQUOTE { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } DL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } UL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } OL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } LI { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } </STYLE> <META content="MSHTML 6.00.2800.1170" name=GENERATOR></HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2>I wrote of this before, what do you = think of my method, Ron. I mean, who needs a dial indicator when you have a business = card?</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV> <DIV><FONT face=Arial size=2>"David, and all, your method is quite a = bit like mine. Rather than buy a Jaras tool, you can do the same thing without = it. </FONT></DIV> <DIV><FONT face=Arial size=2>    What you're looking = for is the fact that when the balance rail contacts the keybed the keys will begin = to raise. I take a business card and cut it so that it's just a little = taller than the keybed-keytop distance. When you put it under the keytops, it will = form a slight curve. Then, I put the balance rail bedding tool on the glide = and, as you describe, push down on it. If it's not bedded you can see the card flex = quite dramatically. Then you can turn the glide bolt in, and as soon as the = glide bolt contacts, the card will start to straighten out. Work from the center = out, when you're done, you can do the "lift and tap" final check. </FONT></DIV> <DIV><FONT face=Arial size=2>    This get's you real = close, real fast. </FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>    Hey, a card's a lot = cheaper than any other tool I know. </FONT></DIV> <DIV><FONT face=Arial size=2>Kevin."</FONT></DIV></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><BR></DIV> <BLOCKQUOTE dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV>"Bobbing [adjacent] hammers" is a clear indication that not all = glide bolts were accurately adjusted.</DIV> <DIV><BR></DIV> <DIV>I remember back about 1990 when a Steinway tech visited Sydney = for a three day technical workshop. Two grands were to be regulated by a = small group of invited technicians.</DIV> <DIV><BR></DIV> <DIV>On the first day the usual paper shim under the bolts, lifting = and tapping procedure was demonstrated by the Steinway technician, to show = the locals just how it was done. I wasn't impressed since we had for some = years been using our own dial-indicator procedure (which is accurate and = quick - a while back the PTG published one of my documents detailing this = procedure in the Journal).</DIV> <DIV><BR></DIV> <DIV>On the second day of the seminar I bought in my dial indicator = and wooden mounting block, to demonstrate our procedure. Sure enough, the glide = bolt adjustment was 'all over the shop'. The visiting tech seemed = unimpressed with our alternative procedure. It never ceases to amaze me how many folks = stick with an inferior procedure just because its 'the way we've always done = it'.</DIV> <DIV><BR></DIV> <DIV>Anyhow, for those who may be interested in our procedure, I will = take you through the process.</DIV> <DIV><BR></DIV> <DIV>A dial indicator is mounted in a small wooden block with a single = hole sized to create a slight interference fit with the rear plunger cover = of the dial indicator (see diagram below).</DIV> <DIV><BR></DIV> <DIV align=center><IMG src="cid:001401c321a0$2e872a80$6401a8c0@ph.cox.net"></DIV> <DIV align=center><BR></DIV> <DIV>The mounted dial indicator is used to set exactly the adjustment = of each glide bolt, so that each just makes contact with the key bed. After = the precise contact position has been established, each bolt is = re-adjusted down a further small amount to ensure that the key frame doesn't lift the = glide bolts clear of the key bed during variable weather conditions.</DIV> <DIV><BR></DIV> <DIV>The procedure we use is as follows;</DIV> <BLOCKQUOTE> <BLOCKQUOTE><BR></BLOCKQUOTE> <BLOCKQUOTE>* All glide bolts are adjusted up to clear the key bed = while the touch blocks are fitted to the piano and tightened. If an = action has mid section glide bolts (eg. Yamaha) you will need to remove a key = over each one to enable adjustment access with the action in the piano. = These also are initially adjusted to clear the key bed.</BLOCKQUOTE> <BLOCKQUOTE><BR></BLOCKQUOTE> <BLOCKQUOTE>* The dial indicator is positioned right next to each = glide bolt in turn, with the wooden block resting on top of the balance = pins while the dial indicator plunger is depressed by the underside of = the pin block (and showing a measurement which is mentally noted). The = adjacent glide bolt is adjusted down until the dial indicator moves just 1 = thou' or 0.025 mm. This procedure is repeated for all glide bolts until all = are just contacting the key bed.</BLOCKQUOTE> <BLOCKQUOTE><BR></BLOCKQUOTE> <BLOCKQUOTE>* Now repeat the adjustment procedure again, only this = time adjust all glide bolts down a further 5 thou' or 0.125 = mm.</BLOCKQUOTE> <BLOCKQUOTE><BR></BLOCKQUOTE></BLOCKQUOTE> <DIV>That's it!</DIV> <DIV><BR></DIV> <DIV>The reason behind adjusting the glide bolts to a just-contacting = setting, before finally pre-loading the balance rail, is that the initial 1 = thou' or 0.025 mm adjustment will not cause any positional change of the = balance rail which might interfere with the initial setting of the other glide = bolts. The end result is absolutely accurate and, provided that the front and = rear contact surfaces of the key frame to key bed are accurate, it will be = quiet and there will be no 'bobbing' hammers.</DIV> <DIV><BR></DIV> <DIV>Dial indicators are generally available at any good engineers = supply. The one illustrated above was lifted from the Cutting Tool Mall website = at;</DIV> <DIV><BR></DIV> = <DIV>http://www.cuttingtoolmall.com/catalog/standard.cfm?FamilyID=90010= 0</DIV> <DIV><BR></DIV> <DIV>Cutting Tool Mall is in New York state, they sell on-line, and = the prices look OK. Furthermore, when used with a magnetic stand, the dial = indicator can be used between the plate and the bridge as the definitive tool for = adjusting the set bolts. We set-up our pianos with the set bolts just contacting = the plate in its resting position. There are many uses for a dial = indicator in piano work.</DIV> <DIV><BR></DIV> <DIV>On my return trip from the 2001 Reno convention I called on = Richard Davenport and toured his LA workshop. Richard had independently come = up with the same idea of using a dial indicator for setting the glide bolts. = So all roads do lead to Rome.</DIV> <DIV><BR></DIV> <DIV>Best,</DIV> <DIV>Ron O.</DIV> <DIV><BR></DIV><X-SIGSEP><PRE>-- </PRE></X-SIGSEP> <DIV>_______________________<BR><BR>OVERS PIANOS - SYDNEY<BR>Grand = Piano Manufacturers<BR><BR>Web: = http://overspianos.com.au<BR>mailto:info@overspianos.com.au<BR>__________= _____________</DIV></BLOCKQUOTE></BODY></HTML>