This is a multi-part message in MIME format. ---------------------- multipart/related attachment ------=_NextPart_001_0016_01C32165.82285280 Re: No Power Yamaha revisited (accurate bedding adjustI 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? "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.=20 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.=20 This get's you real close, real fast.=20 Hey, a card's a lot cheaper than any other tool I know.=20 Kevin." "Bobbing [adjacent] hammers" is a clear indication that not all glide = bolts were accurately adjusted. 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. 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). 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'. Anyhow, for those who may be interested in our procedure, I will take = you through the process. 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). 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. The procedure we use is as follows; * 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. * 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. * Now repeat the adjustment procedure again, only this time adjust = all glide bolts down a further 5 thou' or 0.125 mm. That's it! 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. Dial indicators are generally available at any good engineers supply. = The one illustrated above was lifted from the Cutting Tool Mall website = at; http://www.cuttingtoolmall.com/catalog/standard.cfm?FamilyID=3D900100 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. 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. Best, Ron O. --=20 _______________________ OVERS PIANOS - SYDNEY Grand Piano Manufacturers Web: http://overspianos.com.au mailto:info@overspianos.com.au _______________________ ------=_NextPart_001_0016_01C32165.82285280 An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/fb/1b/03/c7/attachment.htm ------=_NextPart_001_0016_01C32165.82285280-- ---------------------- multipart/related attachment A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 17893 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/ff/b1/dd/50/attachment.jpe ---------------------- multipart/related attachment--
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