I decided to design an End Stop, Z Axis, for the Steel Prusa.
It requires a bit of sanding for a good fit on the contact parts with the printer frame.
VERY VERY VERY IMPORTANT NOTE:
When you touch the end stop switches pay particular attention at the connections. In particular pay attention that no wire gets detached from the switch itself, as if it makes a short you could fry the Ramps and the Arduino Mega.... and guess who have I learnt from?
The X Axis End Stop MOD costed me 35 Euros in Ramps/Arduino/1Driver.
So always be careful when you change pieces in your printer.... UNPLUG IT!
Extra things you need: