Update April 2017: If you are looking for more customization, see also Version 2!

I like the nice design of LucaCap's rear bed leveling sensor holder (http://www.thingiverse.com/thing:1883473). All credit for the fantastic design and idea goes to him! Nevertheless, the original design requires to tap threads into the metal bearing.

This modified design is equipped with plasic dowels, which fit in the (non-threaded) holes on the back of the linear slides and are secured with M3 screws (e.g. M3 x 10mm). NO THREAD TAPING REQUIRED!

The download section holds a version for a 18mm, a 12mm as well as for a 8mm sensor!

Note: depending on your sensor and your cable management you may loose some centimeters of available print height due to a interference of sensor and printer frame.

Firmware configuration:
Due to the altered sensor position the following changes have to be done in the configuration.h file (search vor the capitalized string and adapt the subsequent numbers):
With my E3Dv6 mount / carriage:
#define X_PROBE_OFFSET_FROM_EXTRUDER 0
#define Y_PROBE_OFFSET_FROM_EXTRUDER 50

With the stock carriage:
#define X_PROBE_OFFSET_FROM_EXTRUDER 26
#define Y_PROBE_OFFSET_FROM_EXTRUDER 50

Additionally for all setups:
#define FRONT_PROBE_BED_POSITION 50

(Note for those who don't own a sensor yet: I use this sensor)