you wrote: > > > I'm curious if anyone has a good technique for getting all of those > dowels or blocks to come into contact with the bottom of the plate at > the same time so that the plate isn't put under excessive stresses. > Any thoughts??? > > Thanks, > > Brian Trout > Quarryville, Pa. Dear Brian, I may be able to help you with a technique to reestablish the correct heights of plate support dowels such as those found on Steinway and Mason and Hamlin grands. The method I learned from Angelo Andino, formerly with the belly department at Steinway, is fast and suitably accurate. It doesn't require any of those overly elaborate setups that were mentioned on this list earlier. Often over blown methods are done more for an ego boost than with regard to efficiency. The method I will explain below is essentially the same as that used originally in the manufacturing process. During the pinblock to case fitting one or more spacer blocks supports the plate at the tail. There is no soundboard in the case yet so the spacers support the plate off of the rast. With Steinway pianos the initial spacers are 10 to 12 mm thick. Plate height is checked in various ways including string height and minimum dowel height (no less than 7mm in the high treble and no less than 8mm everywhere else). Once the Pin block is fitted to the case and the plate position is correct the block is glued in. With the plate screwed to the block and the spacer blocks in place the distance between each plate boss and the rast is measured. I use a set of calibrated wood gauges. The dowel schedule is noted on paper. The soundboard is ribbed, fitted to the case. With the soundboard dry fit to case and the plate installed the indexing holes are drilled. Nose bolts and plate lag holes are transferred to the board's surface as well. The re-capped bridge is now glued to the board. Finding the plate dowel height is now simple. Measure the thickness of the soundboard at each lag hole mark. Subtract this from the rast height and you now have the dowel height schedule. These measurements are then used along with the wood gauges to set the bearing. The soundboard is dry fit to the rim with the gauges on top. Then the plate is screwed to the block and clamped at every other bolt hole (go bars are used to clamp the board to the belly rail). Bearing is set (for more information see part four of my down bearing article in the Nov. 95 Journal). The bridge is notched pinned and the board is glued into the case. The gauge blocks used as strand-ins for the dowels are used again to test the dowel schedule and any changes noted (again see the article for information on changing dowel heights). The dowels are cut to height using metal gauges with holes in them. I have a set given to me by Angelo that was used at the factory. They are made from mild steel about three inches long by two inches wide. The corners are rounded and two sets of 9/16" hole are drilled through spaced apart the distance between the dowels. They are of various thickness' from 1/2mm to 2mm and are used stacked together to arrive at the dowel height. A small veneer saw is used to cut the dowels flush with the steel plates. It takes a lot of text to describe what a few slides from my class "Efficient Techniques for Soundboard Building" clearly shows. Another technique I had a chance to use recently comes from Greg Hulme a friend and fine piano re-builder in Kansas City. I have been working on a Bechstein A. I made and installed a new soundboard and pin block, re-engineered the scale and made a new bridge that allowed for a smooth string length transition at the breaks. After all this work I needed to find the thickness of the plate support liners. The original liners were removed without damage but were a little thin in the tail area. I laminated spruce to the bottom of the liners so I could re-thickness them. Greg's technique works with the soundboard already glued into the case. The plate is screwed to the pin block and supported with the two nose bolts in the hitch pin field. The nose bolts are adjusted until the plate is properly set. Use a caliper to measure the height from the board surface to the top of the plate through the plate lag holes. Note the dimensions. Remove the plate and measure the thickness of the plate at each hole. Subtract this from the heights and you now know the thickness of the liners. I planed the liners to these measurements. You may find this technique useful when the soundboard is already in the case. Just cut the old dowels flush with the board, measure, drill for new dowels (Steinway's are 7/16" diameter), glue them in and cut them with the steel gauges. Sincerely, John Hartman John Hartman Pianos Beacon New York Exclusively Grand Piano Re-building. >From Scratch Soundboards and Keyboards to the trade.
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