Lesson 7 - Regulating the Grand Action

Question 1

What are the steps of Regulating the Grand Action

Answer 1

1. Remove the Action
2. Bed the Key Frame
3. Square and Space the Keys
4. Level the Keys
5. Adjust the Key Dip
6. Travel and Align Hammers
7. The Jack
8. Repetition Lever
9. Hammer Height
10. Letoff/Drop
11. Hammer Checking/Backchecks
12. Repetition Lever Spring
13. Dampers
14. Pedals
15. Strike Line

Question 2

How to Bed the Key Frame

Answer 2

1. Remove action stack
2. number and remove keys from frame
3. reinstall action stack without keys and slide the frame back into piano
4. tap front of key frame to make sure it doesn’t knock (if it does, sand bottom of key frame with sandpaper)
5. place thin strip of paper under glide bolt. if the paper rips because of too much pressure twist the glide bolts to loosen them.
6. Reinstall the keys and slide the action back into the piano

Question 3

How to Square the key

Answer 3

if the key leans use a brass or wooden dowel to apply pressure to the rail pin and straighten the key

Question 4

How to space the key

Answer 4

1. lift the front rail punching.
2. use the offset spacing tool and bend the front rail pin in opposite direction.
3. if the key is too tight or sticking to the rail pin you must ease it
4. if the felt bushings swell and limit the keys movements slightly compress it to free up the key

Question 5

How to Level the Keys

Answer 5

1. to raise keys add paper punching underneath
2. if you level them outside the piano you need to buy key leveling weights (they attach to the end and hold them down like the wippen)

Question 6

How to Adjust Key Dip

Answer 6

1. Press key down to 3/8” or 10mm

2. insert paper punchings as need to level the keys

Question 7

How to Travel and Align Hammers

Answer 7

1. add thin strip of travel paper paper or packing tape under hammer flange to change direction
2. align hammers by loosening the flange screw and moving the hammer in either direction so it is centered on the strings
3. make sure the repetition liver is aligned under the hammer knuckle

Question 8

How to Regulate the Jack

Answer 8

1. turn the regulating screw attached to the jack
2. make sure the jack is directly under the knuckle with the back of the jack in alignment with the back of the wood core of the knuckle

Question 9

How to Regulate the Repetition Lever

Answer 9

1. adjust leveling screw located on back of the lever so the jack is not touching the knuckle when key is at rest
2. make sure repetition lever spring is supporting the weight of the hammer
3. make sure there is .003” or .1mm between jack and knuckle
4. test by pushing down on jack toe with finger and releasing it the jack should move freely back into resting position

Question 10

How to Regulate Hammer Height

Answer 10

1. turn the capstan located on the back of the key
2. set a few samples in each section and remove the action to adjust the rest of the hammers to the samples
3. the distance between resting hammers and strings should be 1 3/4” or 44.5mm.
4. adjust hammer rest rail to 1/8” or 3mm between it and bottom of the hammer shank

Question 11

How to regulate Lettoff/Drop

Answer 11

1. let-off - slowly depress the key until you feel the bump of the jack kicking out. The hammer should be 1/16” or 1.5mm below the string
2. turn the let-off screw to adjust
3. the drop - measure the distance between string and hammer while holding the key down
4. adjust to 1/8” or 3mm by turning the drop screw attached to the hammer flange

Question 12

How to regulate Hammer Checking/Backchecks

Answer 12

1. bend the back check wire forward and backward first at the bottom and adjust the angle at the top.
2. hammer should be checked/caught 5/8” or 16mm from string

Question 13

How to Regulate Repetition Lever Spring

Answer 13

1. Remove action from piano
2. hold down each key so that the hammer checks.
3. let it rise just enough so the hammer is released from the backpack and immediately push the key back down.
4. the hammer should rise to the drop position but not so fast that it bounces back against the string
5. use the spring bending tool to remove spring from slot and adjust the tension

Question 14

How to Regulate Dampers

Answer 14

1. dampers should lift when the hammer is halfway to the string and should rise at the exact same time when the damper pedal is engaged
2. set samples by loosening the screw on the damper lever and raise or lower as needed re-tighten the screw but don’t over tighten
3. loosen the rest of the damper lever screws
4. use a wooden block to wedge under the damper lift so the damper levels are all the same height as the samples.
5. tighten all the damper lever screws
6. if the wires do no line up with the felt properly use a pair of flat pliers and adjust the bottom of the damper wire above the lever and twist it to the correct position
7. place action back in piano and play a note and hold down the key
8. press the damper pedal with foot. the dampers should rise no more than 1/16” or 1.5mm above the damper of the key you are holding down

Question 15

Sustaining Pedal

Answer 15

1. lifts all dampers when pressed.
2. there should be 1/8” play in the pedal before dampers lift.
3. loosen or tighten the bolt at top of pedal rod

Question 16

Sosenuto Pedal

Answer 16

1. lifts only the dampers of the keys that were struck before the pedal was pressed.
2. lip of the sostenuto rod needs to be 1/16” away for the tabs and 1/16” above them when not engaged

Question 17

Soft Pedal

Answer 17

1. moves entire action to the right so one less string is played when hammer strikes.
2. screw on right cheek/key block is used to regulate how far the action will shift when pedal is pressed.
3. adjust the screw so that the hammer only hits the strings it needs to when pedal is pressed

Question 18

Regulate Strike Line

Answer 18

1. moving action forward or backward can change the volume of the notes dramatically
2. there are usually wooden brackets that hold the back of the action in place that can be adjusted by a screw
3. there also might be a small bracket in the cheek or key block that can also be adjusted by a screw
4. with key blocks out. adjust the action so high treble rings loud and clear.
5. when adjusted place the key blocks back in place so the action guide pin moves the brackets to the correct position.