Regulation of backcheck (wire) of upright piano for quality double repetition.

[themaximillyan]

The purpose of regulating the double strike of the piano hammer on the string is as follows: we need to understand how the piano mechanism works. We press a key, which has a rod with a barrel at the end (capstan*). This capstan comes into contact with the* whippen*. The whippen has* a jack*, which is a movable stick on a spring that moves here and activates the hammer. The hammer has a part called the* balance*, and the whippen has a part called the* backcheck*. The ability to increase the number of strikes the hammer makes on the string here depends on how the balance and backcheck are adjusted relative to each other. In the video, you see* Mr. Vladimir Sukhopyatkin demonstrating how he achieves an increase in these strikes on the string by bending the backcheck wire. When it is not working correctly, the jack comes out from under the hammer after striking the string, and the hammer falls very deep onto the backcheck here. And when we try to do a double repetition here, we cannot achieve it because the jack has slipped. On the notes A and B, Vladimir Sukhopyatkin adjusted it in such a way that the backcheck immediately "catches" the balance, allowing the jack to repeatedly activate the hammer. What do you need to do? It's a simple operation: you are trying to push the backcheck wire away from you. This creates the possibility of a double repetition.