<HTML>In a message dated 12/21/2002 4:52:52 AM Pacific Standard Time, mfarrel2@tampabay.rr.com writes: <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Subj: Re: Soundboard Clamping for Downbearing Date: 12/21/2002 4:52:52 AM Pacific Standard Time From: <A HREF="mailto:mfarrel2@tampabay.rr.com">mfarrel2@tampabay.rr.com</A> Reply-to: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A> To: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A> Sent from the Internet            Terry</BLOCKQUOTE>                  I left out that I also clamp the board at the belly rail, spine and am particularly careful to get the upper most treble edge firmly down on the rim either with clamps or by using the preexisting screws and holes for the maple trimmed edge that is on most pianos. A small error at that spot will yield you (0 ) bearing after the boards glued in and you will gnash your teeth.. Actually gluing the board in locates it at its  true and final elevation and small mistakes on the top treble cap are easy. Ask me how I know?      You didn't ask but you probably will. How do you get the plate reset on the acoustic dowels? I thought you'd never ask. This is a Gravagne idea so I cannot take the credit, oh well.   I use half inch cap screws. This is a large machine type screw with an allen head opening in the top. The top is to thick dimensionally to imitate the thickness of the original heights of some of the very short elevations of acoustic dowels. So the tops are machined to about . 050. Stay with me. Now when the time comes to find the height of the new dowels that the plate will sit on, these are inserted in the bolt holes. I drill down thru the boards thickness only, remember up to now no bolt hole is in the new board, with a 1/2 inch forstner bit (flat bottom bit) Then I take a 7/16 forstner and drill down another 1/4 inch. This allows the threads of the cap screw to bite into the rim and not the board as the board will split  as the cap screw is turned in if just a 7/16ths hole is drilled  thru the board. Get it? Then a cap screw is located in each bolt hole location and screwed down to a reasonably low level using a large allen wrench.   Then the plate goes on. The nose bolts, already installed earlier, will now be what now locates the plate height you set earlier. Install the nose bolt nuts and accessing the top of each allen head through the plate screw it up until you sense it touch the plate. Repeat on each one and there you have the jigs set up to mark the dowels for there final and correct height.     Pull the plate and drill the acoustic dowel holes. I drill a 7/16 hole. I use the 7/16 inch hard wood dowel from pianotech which is conveniently slightly smaller than the hole so that I can insert the dowels mark the height, remove them, cut and reinstall. I use a mirror to see at the level of the board so I accurately observe when the dowell height matches the top of cap screw height. Does all this make sense or did I leave something out?      There are a many details in belly work that you must learn to juggle  in your head at one time so that all the inter related pieces  fit in to the re appropriate spot at just the right time. This is just another one of those pieces.                      Hey When it turn out it's slick!                                Dale Erwin <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px"> Wonderful, wonderful. Thank you Dale. This sounds like a system that I can work with. Terry Farrell Dale wrote: >      Well, it certainly is way easier to do the bridge notching / >pinning, etc., out of the piano. >  So I do the dry fit set up this way. In my climate I like the board to have >taken up some moisture but something like it would experience with the R. H.  >about 40% or EMC about as you said 9% or so. I locate and temporarily install >my bridge to the board with soundboard buttons and screws, one between each >rib and one through only the ribs in the low tenor that have the feet thing >and cutout between them. Usually that's only 2 or three. I Install the board >dry by drilling holes for dry wall screws thru the board and into the rim >where the acoustic dowels were located. No magic here. These holes will >eventually disappear when the holes for acoustic dowels are drilled or fill >them with hammer shank if a different support system is used. >  Next install your plate with the nose bolts for support. Install about 8 or >10 screws in the pinblock, usually next to each strut. I set the plate so its >elevation at the last bass end bolt hole is where it was originally which >means the plate boss is fairly close to the board. I have a shim between the >boss and the board. I put a clamp and block holding down the plate to prevent >it from coming up in the bearing procedure. >   I then turn up my nosebolts which were installed low. This includes the >bass strut nose bolt and cap nut too. I pre-stress the board with a shim at >each plate strut to simulate some string load as I've described before. I Cut >my bearing notches to determine where the bridge height will be. Pull the >plate &board plane the top of the bridge reinstall check and make final >corrections to height and bridge slope. Pull it out remove the bridge, drill, >notch &pin and the other details. >   After the board is glued in I always recheck my bearing and adjust my >plate a bit if needed. This is a great method but you'll find your board ever >much stiffer when you go thru the pre-stress bearing check at this point >because the bridge and board have been glued on and everything has gotten >stiffer. Which means your bearing may be more than you bargain for. With this >method I've learned to set the distance bearing on the stingy side especially >from about note 60 ish on down. With Steinways it's possible to shim aliquots >up if too much bearing is attained. Flexing the plate up with the nosebolts >is good for about 1/4 turn max. in my book with Steinways and none in Masons >as the plates are too stiff to flex. >    Hope that helps >     Dale Erwin </BLOCKQUOTE> </HTML>