Subject says it all really, I'd really like to be able to press a button on Shuttle & then the Z plane on my DIY CNC goes to a set location.

This is becuase when MAch3 promps for a tool change, I have to jog the Z plane up far enough to remove the tool - this is starting to get a bit monotonous now! Far better just to press a button & have it happen.

I don't have homing switches....perhaps there's some other way I can achieve my goal?