Kawai SK-7 Reference guide

１
KAWAI GRAND PIANO
REGULATION MANUAL
Ver 1.4 2011/7/21
Piano Laboratory
Supervisor Kazuo Goka

２
Regulation Process Index
１ Tighten all Plate Screws・・・・・・・・・・・・・・・・・・・・P3
２ Strike Point, Keyframe Position ・・・・・・・・・・・・・・・・P4
３ Ease Keys ・・・・・・・・・・・・・・・・・・・・・・・・・・・P5
４ Bed Keyframe・・・・・・ ・・・・・・・・・・・・・・・・・・・P7
５ Travel, Angle Hammers ・・・・・・・・・・・・・・・・・・・・・P8
６ Space Hammers to Strings・・・・・・・・・・・・・・・・・・・・P9
７ Space Levers to Knuckls, Whippens to Capstan Screws ・・・・・・P11
８ Repetition Spring ・・・・・・・・・・・・・・・・・・・・・・・P12
９ Jack Alignment, Height ・・・ ・・・・・・・・・・・・・・・・・P13
１０ Key Height・・・・・・ ・・・・・・・・・・・・・・・・・・・・P14
１１ Hammer Blow Distance・・・・・・・・・・・・・・・・・・・・・・P15
１２ Hammer Rest Rail・・・・・・・・・・・・・・・・・・・・・・・・P16
１３ Hammer Letoff ・・・・・・・・・・・・・・・・・・・・・・・・・P16
１４ Hammer Drop ・・・・・・・・・・・・・・・・・・・・・・・・・・P17
１５ Key Dip ・・・・・・・・・・・・・・・・・・・・・・・・・・・・P17
１６ Back Checks ・・・・・・・・・・・・・・・・・・・・・・・・・・P19
１７ Back Stop ・・・・・・・・・・・・・・・・・・・・・・・・・・・P20
１８ Repetition Spring (re-check) ・・・・・・・・・・・・・・・・・・P20
１９ Balance Rail Studs・・・・・・・・・・・・・・・・・・・・・・・P21
２０ Damper・・・・・・・・・・・・・・・・・・・・・・・・・・・・・P22
２１ Damper Upstop Rail・・・・・・・・・・・・・・・・・・・・・・・P24
２２ Damper Pedal・・・・・・・・・・・・・・・・・・・・・・・・・・P25
２３ Sostenuto ・・・・・・・・・・・・・・・・・・・・・・・・・・・P26
２４ Una Corda ・・・・・・・・・・・・・・・・・・・・・・・・・・・P27

３
１．Tighten all Plate Screws
The plate will have countersunk screws which
should be checked for tightness using ratchet
handle with Phillips No. 4 head, or similar. On a
new grand piano the screws should be checked
carefully, because the bolts are lubricated when
installed and can be overtightened. Even on an
older piano we would not expect to get much more
than one quarter turn on some of the screws.
For Shigeru Kawai pianos only, plate screws have 2
types. There are hexagonal head screws around
the outside, countersunk Phillips screws on the
pinblock section. These should be tightened with a
17mm socket for hexagonal screws and Phillips No.
4 head for the countersunk screws, as with the
regular Kawai models.
*Note: Shigeru Kawai pianos now use a machine
bolt around the rim perimeter. This is threaded
into a steel plate support, and should not need to be
tightened.
*Some old Kawai pianos use 14mm screws around
outside and a pin block area.
Caution: Do not tighten the nose bolts.
Other case parts such as hinge screws, music desk
glide screws, lock bar screws, etc. may be tightened
as required.
BE CAREFUL TO NOT OVER TIGHTEN
SCREWS. THEY CAN BE OVER-TURNED OR
BROKEN.

４
２．Strike Point, Keyframe Position
Hammer No. 88 should strike the string 2.16mm
- 3.0mm from the capo bar. The final location
should be chosen by the sound.
To move the action forward glue a shim (thin wood
veneer) onto the hard wood block at the back side of
the Keyframe. To move the action back, file the
wood block. After the block is set correctly, then
adjust the keyframe guides in the cheek blocks to
match.
If most hammers are aligned towards the left from
strings, glue a shim (wood veneer or thick paper) to
the back side of Action Block.

５
３．Ease Keys
3.1 Front hole bushing
While holding the balance rail, check the lateral
movement of the keys in the rest (up) position.
Also check with the keys in the depressed (down)
position. Proper gap should be 0.2 mm to 0.3mm,
with a small but clear “knock” sensation.
Easing a tight front hole bushing using key pliers
3.2 Balance hole bushing
Check the lateral movement of the keys in the rest
position (up) and in the depressed (down) position.

６
Ease any tight balance hole bushings with key
easing pliers.
Lift up the Key back 1 – 2mm and release. It
should fall down slowly by its own weight, without
sticking. For best results, key should fall more
slowly in dry conditions, and a little faster during
humid conditions.
If the key sticks then ease the balance hole. This
process must be done carefully until the key moves
with the desired ease, but is not too loose.
*Do not ease the front and back of the balance rail.
Only ease the sides of the hole by turning the
easing tool inside the key so that the flat surfaces
face front to back, then apply pressure to the hole.
*If the balance hole is loose on the pin, apply a few
drops of alcohol and water (Isopropyl 70%) to the
hole then set aside. Once it is dry, re-fit it to the
pin.

７
４.Bed Keyframe
Raise all of the bedding screws so that they are not
in contact with the keybed.
Place the fingers of one hand against the front rail
and keybed, then tap the keybed with 3 fingers of
the other hand. Listen for a knock noise and feel
for movement between the front rail and the
keybed.
If there are loose areas, pull the keybed out and
trim the tight areas with a plane or sanding block.
As you remove wood from the tight areas, the loose
areas will settle down and become tight
* Note: It is normal for the keyframe front rail to
lift up at the ends during dry weather. Be aware
of the relative humidity when bedding the
keyframe
For the back rail, remove the keys and tap on the
action bracket supports to check for knocking. If
needed, trim the bottom of the back rail at the tight
areas with a hand plane or sanding block, which
will lower the loose areas and eliminate knocking.
Adjust the pressure screw in the cheekblock for
light pressure on the guide pins. This will prevent
knocking of the keyframe during dry weather.
*Note: Keep the balance rail bedding screws
raised until later in the regulation process. This
prevents errors in setting the key height and key
dip.

８
５. Hammer Travel & Angle
Lift a group of hammers by hand or with a straight
edge and look for sideways movement as the
hammers travel upward.
When the hammer was down, the hammer was
evenly spaced. When raised, the hammer has
moved to the side, indicating that it is not moving
straight up.
Place a piece of travel paper between the flange
and hammer rail on the same side of the screw as
the direction the hammer is traveling. Differences
in thickness or length of paper will determine the
degree of correction.
*Note: the travel paper should not be visible once
the flange is screwed back into place.
Check the hammer angle at rest position. If the
hammer molding space is equal but hammer tip is
not equal, the hammer is angled.

９
Checking hammer angle – spaces between
hammers must be equal and parallel at the “rest”
position.
If an error is detected then the shank can be heated
up and then carefully and very gently twisted back
into the correct alignment position.
*Do not use excessive force as this will stress the
flange and possibly damage the bushings.
After the hammer angle is corrected.
６．Space Hammers to Strings
For single and bi-chord notes, the hammers should
be centered under the strings.
*Note: Double-check that the soft pedal is adjusted
to allow the action to return all the way. Press the
soft pedal and insert a strip of paper between the
keyframe and the action stop block. Release the
soft pedal and the keyframe will return and trap
the paper strip. The paper should be firmly
gripped and cannot be pulled out until released by
again pressing the soft pedal.

１０
The contact point of the hammer is centered under
the bi-chord strings.
In the trichord note section the bass side of the
hammer should overlap the left string 1mm.
For easy hammer spacing, put 1mm shim (metal
ruler) between keyframe and action stop block
Use the Hammer flange spacer under the pin block
while looking down between the strings.

１１
With the 1mm ruler in place, adjust the left edge of
hammer to be even with the left string.
After all hammers are spaced even with the
strings, remove the metal ruler from the action
stop block.
７．Space Levers to Knuckles, Whippens to Capstan Screws
The knuckle should be centered on the repetition
lever, the capstan on the repetition cushion and the
jack on the regulating button.
To adjust lateral position of the wippen, loosen the
screw and shift the wippen over, or insert a piece of
traveling paper behind the wippen flange on the
side that you want the wippen to move towards.
To position the jack tender under the let-off button,
insert traveling paper underneath the side of the
wippen flange that you want the jack to move
towards.

１２
When spacing wippens, use a mirror to watch the
jack tenders, and also verify that the wippen heels
are centered on the capstans.
８．Repetition Spring
Strike the key normally and slowly release. The
repetition spring should carry the hammer back up
in a slow, easy movement without jumping or
catching. If the movement is too slow, dislocate the
top section of the spring and pull upwards.
If the movement is too fast, press the spring
downwards as shown.
*When pressing or lifting the spring, you need to
only change the shape of the coil portion of the
spring, not the shape of the curve area.
*Always re-check the spring strength with the
action in the piano.

１３
９．Jack Alignment, Height
Align jack
Align the back of the jack (nearest the hammers) to
the back of the wood core of the knuckle by turning
the jack screw in or out. When checking the
alignment, be careful of your eye angle to make
sure the jacks are aligned correctly.
Repetition Lever height
The top of the jack should be placed slightly lower
than the repetition lever (0.1 mm to 0.2mm).
When turning the regulating screw, depress the
repetition lever to avoid damaging the felt button
and pad.
To check repetition lever setting:
To check the repetition lever height, with the
hammer in the “rest” position gently and slowly
press down the jack heel. The hammer should
barely move. If it drops but doesn’t return when
the jack is released, then the repetition lever is too
low. If the hammer does not move when the jack
heel is pressed, then the repetition lever is too high.

１４
１０．Square and level Keys
Should be 66mm to 68mm from Keybed to the top
surface of the white key, depending on the model.
Set sample keys at each end, then level all keys
with a straightedge.
MODELS NEOTEX
SKEX EX GS100 68.0mm
SK-7 RX-7 68.0mm
SK-6 RX-6 RX-A RX-B 66.0mm
SK-2.3.5 RX-2.3.5. 66.0mm
Place thicker punchings lower on the pin, and
thinner punching paper above, just under the felt
punching.
Square the keys so that the top surfaces are
horizontal, by tapping the balance pin side to side.

１５
Adjust Black Key Height 12.5mm from White key
top.
１１．Hammer Blow Distance
Set sample hammers to the correct blow distance
at both ends of each section. Hold the blow
distance gauge between one hammer and the
string, then adjust the capstan on the next
hammer so that it matches the sample. The blow
distance should be 46mm.
Once sample hammers are set, slide action out and
regulate the capstan screws in the remaining
hammers to form a straight line.
Level Hammers in each section using the capstan
screws.

１６
１２．Hammer Rest Rail
Set the hammer rest rail 5mm below the hammer
shanks in the rest position.
１３．Hammer Letoff
Adjust hammer letoff Distance.
To improve accuracy, place a light directly above
the string and watch the string’s shadow on the
hammer felt.
Press each key down slowly with one hand while
adjusting the letoff dowel with the other hand to
set the letoff distance.
In the bass section letoff should be 2.0mm - 2.5m,
middle and treble 1.0mm - 1.5mm.

１７
１４．Hammer Drop
Regulate each hammer so the drop screw touches
the top of repetition lever at the same time the jack
should touch the regulating button. The initial fall
distance of the hammer will be the same as the
letoff.
*Make sure to re-check this with the action in
position in the piano itself.
１５．Key Dip
15.1 White Key Dip
Using a dip block, 10.1mm, depress each key and
compare with height of the neighboring key. Add
or subtract punchings until desired dip is achieved.
Put paper punchings under cloth.
*Make certain that the same pressure is used
throughout the key board. Move back and forth to
re-check your finger pressure as you regulate.
Another way to double check for evenness is to
push down 3 keys with 3 fingers using same
pressure and compare the Dip.
*Thicker paper lower, thinner paper upper.
Maximum of 4 of any one size.

１８
15.2 Black Key Dip
Set the black key dip by comparing the feel of the
aftertouch in the white keys with that of the
neighboring black keys. Remove or place
punchings underneath until the aftertouch feel is
the same. Put paper punchings under cloth.
Thicker card and paper should be lowest on the
pin, thinner paper upper. There should be no
more than 4 of any one thickness paper.
Black keys should be about 2mm higher than
white keys, when black keys pushed down to
bottom.

１９
１６．Back Checks
Correct backcheck angle.
If setting the backchecks to the correct specification
(15mm from string) results in the hammer tail
dragging on the backcheck during
fortissimo
playing, then the backcheck angle is too steep.
When key is played and the hammer is in check,
tap the hammer down into the backcheck. If the
hammer can be pushed down all the way, then the
backcheck angle is too vertical.
Alignment
Using bending pliers, space the back checks so they
are even and square to the hammer tails. The back
check wire must be bent twice, once at the bottom
and the opposite way at the top.
The backchecks must be uniformly spaced and
their back surfaces parallel to the hammer line

２０
１７．Back Stop
The hammer top should be an average distance of
15mm from the strings with the key is played and
the hammer is in check. Set the outer key of each
section then align the other keys.
Check to see that the hammer tails do not drag on
the back check by moving the key with one hand
and pushing down on the hammer with the other.
If the tail drags, adjust the angle of the back check
again.
１８．Repetition Spring (re-check)
Re-check the repetition spring regulation after setting the backchecks.