RE: Reproducing Mechanisms in Concert Grands
By Craig Brougher
I was interested in the arrangement mentioned by Brian Thornton regarding concert hall concert grand motor arrangements. I retrofitted a gutted concert Chickering a few years ago too, and noticed that there had once been mounted three motors. Two ac motors, and one dc motor. The two ac motors I learned, were shived together, and then a large motor pulley drove the pump at about double speed. The dc motor was used for those stages that had dc power.
I got around the double motor arrangement by taking a later model "B" motor to the motor shop and having them wind it in such a way that it doubled its power so I could use the oversize pulley. But if your crankrods in the pump are maple, they will not stand up under that pressure very long. The rods started to knock after two weeks of playing. So before I went to the expense of replacing everything will ball bearings, I made another set of wooden rods from the highest quality delignite pin plank material, and I made them as extra wide as I could possibly get in. It was a great choice. And to this day, I am told that piano is "peeling the wallpaper off the walls."
Craig B. craig_brougher@msn.com |
(Message sent Mon 6 May 1996, 14:44:42 GMT, from time zone GMT.) |
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