Page 1 of 1

Dimensions of keys on various instruments

Posted: 16 Sep 2011, 17:14
by Hanon_CTS
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

Image
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


Image
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

Image
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

Image
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


Image
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


Image
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


Image
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

Re: Dimensions of keys on various instruments

Posted: 18 Sep 2011, 21:00
by iaorana
Thank you Hanon :thumbup:

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 :thumbdown:

To estimate this parameter without dismantling the instrument, you can build a "gauge" (I used Lego :angel: ) 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 8-)

Alain

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