What is Regulation and Does my Piano Need it?
Regulation is done whenever we replace the felt under the keys, replace hammers, damper felts, etc.
In simplistic terms, it is adjusting the mechanism to perform optimally.
First, the height of the keys need to be determined.
To adjust the height of the keys, and to level them, you add or remove paper washers under the bkeys, on the balance rail, where the keys pivit.
To adjust the keydip, “how far the key presses down”, you add or remove paper washers at the front of each key, on the front rail.