Homemade button to test how hard it was hit

Are you interested in discussions about "fully weighted" vs. "graded soft touch" keys ?

Yes I am, but first I want to work out the best way to solve the problem of velocity reading - using standard parts

If you want to tell how hard a hit is you need to set some kind of range. You can use a spring and a pot to tell how hard the hit is

Yeah ive thought of this, but unless you know a company that produces these by the millions, and sells them cheaply, this would be a major faff to put together and setup, plus its totally mechanical and therefore much more prone to failure.

Grump_Mike:
Is what you're talking about a Dpdt slide switch? They have three connections - the middle one to ground, and the outside two to +5v and a digital pin.
Is this how its usually done is it? I pulled apart a midi keyboard, and they use two push switches per key, and time the time between the two being pressed - hence my light gate idea - anyone want to comment on the pro's/cons of that technique?