What is Regulation?

The (grand) piano action is the mechanical component of a piano and consists of some 10,000 parts. A piano is made up of a harp and a mechanism that strikes the strings on the harp, called the action. The action is made up of the keys and a system of moving parts that translates the movement of the keys into movement of hammers that in turn strike the strings. When a piano is new, the action is adjusted so that it will produce the best feel and response that the piano is capable of.

Regulating the action

Tighten Plate Screws
Key Slip/ Key Height Measurements
Lube Spring & Lever
Tighten Plate Screws
Check Damper & Stop Rail Screws
Remove Stack & Key Strip
Remove Keys
Bed Keyframe (100 – 150 Grit)
Regulate Key Frame Glides
Replace Keys, Stack, Key Strip
Take String Height Measurements
Clean Action
Tighten Action Screws
Reshape Hammers
Remove Stack & Key Strip
Make Necessary Action Repairs
Lube And Polish Capstans
Remove Keys
Sand, Sweep & Lube Key frame
Polish And Lube Front And Balance Rail Pin
Brush & Lube Knuckles (Teflon)
Replace Keys – Check And Ease Front Rail
Balance Rail Bushings And Rail Pin Hole
Regulate Centre Pins And Flanges
Replace Stack
Travel Hammers
Check And Adjust Hammer Spacing
Centre Hammers To String
Level & Space Strings
Possibly Remove Stack & Use Key Weights
Level, Square And Space Keys
Regulate Key Dip
Replace Stack
Check Overall Alignment
Check Repetition Lever/Rocker/Capstan/Jack
Check & Adjust Jack To Knuckle Position
Check & Adjust Repetition Lever Height
Regulate Hammer Height Line
Regulate Hammer Rail
Adjust Let Off
Check Black Key Depth
Adjust Hammer Drop
Align Back checks To Catcher
Adjust Back check Distance/Height
Adjust Angle Of Back checks
Regulate Repetition Spring Tension
Regulate Height Of Key Stop Rail
Centre Hammers To Strings
Level & Space Strings
Remove Cloth, Check All Previous Regulations
Regulate Dampers & Pedals
Damper Guide Bushings
Damper To Keys
Damper Stop Rail
Dampers To Dampers Lift Rail
Sustaining Pedal To Lift Rail
Sostenuto Mechanism And Pedal
Hammer Lift Rail
Adjust Striking Point
Una Corda Pedal
Seat Strings
Raise Or Lower Pitch
Tune To A-440 (Fine Tuning)
Voicing Of New Hammers

Signs that regulation is overdue

Keys seem to go down too far or seem too shallow
Uneven touch from one note to the next
It is difficult to play softly and still have the notes sound
Notes do not repeat quickly
Notes continue to ring after the key returns
Pedals squeak
Piano has developed a harsh metallic sound
Keys rattle, action is excessively noisy

Over time as the action wears in, the felt compacts and the hammers wear, tone and the touch of the piano may start to decline. When this occurs it is time to look at regulating the action and voicing the hammers. Depending on how far the instrument has been allowed to decline this job may take just a few hours or a few days.