Dimensions of keys on various instruments

[iaorana]

Hello all,
I have taken some measurements on the keys of various instruments for reference and comparison.
Dimension A is the natural key's playable width.
B is its' length.
C is the normal depth when depressed "before digging into the aftertouch zone"

D is the distance from the front of the natural key to the front of the sharp key

E is the playable width of the sharp key.
F is its' length.
G is the normal depth when depressed "before digging into the aftertouch zone"

All measurements were taken to the nearest 64th of and inch and converted to decimal inches.
All key surface measurements are at the widest playable point "bottom of chamfer".
{edit} The second figure is in Millimeters


NSEx 76 Fatar TP/40
A: 0.875" 78.56mm
B: 6.0" 152.4mm
C: 0.469" 11.912mm
D: 2.0" 50.8mm
E: 0.344" 8.738mm
F: 3.469" 88.11mm
G: 0.375" 9.525mm



NE3-61 Fatar TP/80
A: 0.859" 21.82mm
B: 5.25" 133.35mm
C: 0.437" 11.1mm
D: 1.844" 46.84mm
E: 0.359" 9.12mm
F: 3.0" 76.2mm
G: 0.312" 7.92mm


Hammond M3 (key dimensions are same as the B3)
A: 0.875" 78.56mm
B: 5.219" 132.56 mm
C: 0.469" 11.91 mm
D: 1.875" 47.63 mm
E: 0.312" 7.92 mm
F: 3.000" 76.2mm
G: 0.312" 7.92mm


Kurzweil K250 "keybed mfg by Baldwin Pianos"
A: 0.875" 78.56mm
B: 5.656" 143.66mm
C: 0.5" 12.7mm
D: 2.0" 50.8mm
E: 0.375" 9.525"
F: 3.25" 82.55mm
G: 0.375" 9.525mm



Korg M3-88 RH3 keybed
A: 0.875" 78.56mm
B: 5.812" 147.62mm
C: 0.437" 11.1mm
D: 1.906" 48.41mm
E: 0.375" 9.52mm
F: 3.437" 87.3mm
G: 0.406" 10.31mm



Roland D-70
A: 0.859" 21.82mm
B: 5.281" 134.14"
C: 0.469" 11.91mm
D: 1.844" 46.84mm
E: 0.344" 8.738mm
F: 3.093" 78.56mm
G: 0.281" 7.14mm



Roland D-50
A: 0.859" 21.82mm
B: 5.437" 138.1mm
C: 0.406" 10.31mm
D: 1.953" 49.61mm
E: 0.328" 8.33mm
F: 3.031" 78.56mm
G: 0.281" 7.14mm

Please feel free to post measurements of other instruments using the same criteria.

Cheers, Hanon

[iaorana]

Thank you Hanon

One very important parameter is missing, though invisible: the key fulcrum (pivot) position!

In cheap all plastic keybeds, the fulcrum is located just beyond the end of the key visible part. Hence the leverage is very short, so it is practically impossible to correctly play, say a F# fundamental chord

To estimate this parameter without dismantling the instrument, you can build a "gauge" (I used Lego ) you put on a white key. This gauge has an arm that extends above the keyboard panel. Now you just have to find the "virtual rotation point" of this arm

Alain

PS: when you US citizens will turn to metric system?