When I first looked at the Brinsmead 1870 concert grand the sostenuto wasn't working and I guessed someone had removed a rail. Once I had it apart I discovered the remains of some twine on the end arm and realized that's all that was missing. I have threaded a thin polyester braided cord through the arms and everything now works perfectly. This is rather a clever arrangement. Instead of tongues built into the damper drop, as on Steinway etc., which requires perfect regularity in the line of the drops, the position of the catcher cannot change, since it is attached to the damper body. The catcher is nickeled brass spring wire and its upward travel is limited by a loop of braid to prevent it touching the drop. The braid loop underneath the body is for the damper string, absent in this case because this body is from the top damper. Another nice feature of the drop is the block of hard felt at the back. This allows you to tighten and loosen the screw without holding the drop, since as soon as you push the drop inwards the felt contacts the beam canitilever behind, so you can press the turnscrew hard into the slot without bending the damper wire. The whole arrangement is very stable. After 140 years all that was needed to get it working perfectly as a piece of string! JD -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20110319/81c67242/attachment-0001.htm> -------------- next part -------------- A non-text attachment was scrubbed... Name: sostenuto_small_01.jpg Type: application/octet-stream Size: 99584 bytes Desc: not available URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20110319/81c67242/attachment-0001.obj>
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