When designing and building my modified version of the Kossel Mini, I didn't wanna use the allen key Z-probe mechanism, I feel it is not a very neat solution. So while waiting for some IR sensors to arrive I designed this detachable probe mount. It snaps on to the underside of the magnets used for my effector joints and works like a charm. Uses the common Omron mechanical switch, and six 10 mm magnets. My effector: http://www.thingiverse.com/thing:881793Print without support with whatever settings you want. Add 6 10x3 mm magnets, attach the Omron switch and connect to printer.