Fig 9Plate and rimDrag or ← → to string notes · Home · Endunstrung
The note just strungCast-iron plate: flange, struts, hitch panel and pin fieldLaminated maple rim and spruce soundboardEvery string pulls between its tuning pin and its hitch pin, so the plate takes all of it: 19.8 tonnes here, with 4.1 t of it in the 20 wound bass notes. The tension is the same scale as Fig 7, note by note: 150 kgf for A0's single string, about 80 kgf for each of the three strings of a mid-range note, 70 at the top. Iron is strong in compression, so the plate is cast as one frame: a flange round the rim with the hitch pins, a front section over the pinblock with the tuning pins, and struts between the string groups to carry the pull from one end to the other. The rim around it is about 18 plies of maple bent together in one press. It stops the plate from twisting, and holds the soundboard at its edge.