Nick~ There is another way of fitting the two step pinblock. I don't know if it is easier or faster than the router table set up, (I haven't tried the router), but this worked well for us. It involves different tools. (No router.) One of the problems with a router setup is that the old pinblock sections sometimes have shrunk away from the plate flange, so if you are using the old pinblock as a pattern or template that way, you could still be off. (Also the router method requires a lot of setup IMHO) The method I used allowed me to individually fit each individual "step" to its respective flange on the plate, just like you would a normal pinblock. If you only want to get "close" to the flange profile and then make up the difference by glassing, I guess that's possible too. Consider the two step pinblock as two layers that can be "disassembled". Measure the overall thickness of the old pinblock, and figure out how thick each layer needs to be. You will be sawing the old pinblock apart, into two layers (or two individual steps). (By the way, this works for all sorts of other double step pinblocks as well. It's how we used to do Victorian Steinways.) Each one of these old pinblock "layers" can be used as a pattern to make the layers of the new pinblock, which can be individually fitted to the plate flanges/recesses, and then glued together, using the plate itself, and clamps, as a fixture. (Just as you would a normal pinblock, make each layer slightly oversize so that it can be fitted to the flange.) Drill the machine screw holes, after the assembly is glued together, in such a way that the bevels on the flathead machine screws pull the block tightly against the plate flange, then mark the tuning pin holes with a machinist's punch. Remove the glued up pinblock from the plate recess/flange and drill it on a 7 degree tilting table on the drill press (or if you want, you can drill it in the piano, if you have the set-up to do that). If you have a bandsaw that has sufficient height (I have the Delta with the height attachment, but you may not need it - as I remember the Chickering pinblock wasn't that deep/wide) you can easily saw the old pinblock apart into the two layers. The bandsaw does make a kerf, so that's why you need to know the thickness before you rip the old block apart. If you use a relatively narrow blade on the bandsaw (say 3/16' or 1/4 " x 10 tpi) it will tend to deflect backwards rather than curving to the side, making a straighter cut than a wide blade. (A trick I learned from Mark Duginske's Bandsaw Handbook). I use a ripping fence on the bandsaw that is angled to compensate for the bias of the blade (have to change it for every blade) but you can just eyeball it as well, or use one of those little resaw point jigs to keep the pinblock vertical while you try and follow a pencil line or the side of one of the "steps". You'll need to make new pinblock layers that are the same thickness as the ones you cut from the old pinblock, plus the kerf. It's easy to make these from stock pinblock panels using a bandsaw to "resaw" them to proper thickness, and then a planer or jointer to surface. You can try to duplicate the original lamination thicknesses, using different types of pinblock blanks, or you can just use something like Delignit. Some pinblocks, we were able to separate the laminations into two layers with a putty knife or chisel. They just sort of fell apart. Others are better sawn. I believe I used dowel centers to locate the machine screw holes in the new pinblock. You can also try using the old pinblock as a drilling template, but that's dicier. I seem to remember on the last quarter grand I did there were basically two pinblock sections, a bass (short), and a treble (long). But other Chickerings we have done have different configurations. One larger grand had four individual pinblock sections. If you want, I took quite a few pictures of the operation I can e-mail you, and give you more details with the actual sequence. It actually went quite fast, from what I remember. Sincerely~ Kendall Ross Bean PianoFinders www.pianofinders.com <http://www.pianofinders.com/> e-mail: kenbean at pianofinders.com Connecting Pianos and People _____ From: Nick Gravagne [mailto:gravagnegang at att.net] Sent: Saturday, July 19, 2008 5:23 PM To: pianotech at ptg.org Subject: Chickering Quarter Grand Pinblock Hello All, I have found myself knee-deep (and delightfully so) in an authentic Chickering Quarter grand rebuild (belly job only). Questions: most of us know about the machine-screwed, two-step pinblock fit to the two-step plate flange (ouch). I understand per my fellow tech and friend, Les Conover of Albuquerque, how to fit the new block using a straight ¾ router bit and a router table set up. Any other (aka simpler?) ideas out there? Also, I would like to replace the agraffes, but the original threaded studs are slightly smaller in diameter than the standard size available today. Has anyone re-bored and re-tapped the holes to accept a standard ¼ stud? Or might it be better to remove and recondition the existing agraffes? Progress thus far: the crowned soundboard is made and fitted to the case; the bridges are underway; and it is now time to begin thinking seriously about the block. Thanks for your consideration. Nick Gravagne, RPT -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20080720/87b7ff41/attachment.html
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