Casio CDP-100

Velocity = [10, 38, 65, 87, 112; 0, 25, 54, 85, 127]

I was able to hear the softest midi value but this curve seemed more realistic in the minimum strike that is needed to make a sound on an acoustic piano.  I also made it a little easier to get the loudest key without having to completely hammer on the keys.

Edit: change title from "Caso" to Casio.  Sorry for the mispelling