Auto bed-level for Ultimaker 2 with original Head

This solution uses a really cheap touch sensor for $0.13 as bed level sensor integrated on the free hole of the second Nozzle.

I'll had some calibration "issues" with my Ultimaker 2 extended (clone). I'd had to repeat the calibration procedure every 1-2 Weeks. It was pretty annoying for me.

The generic sensors are pretty big and will result in loose of print space. Most of them are even to big to mount them inside the printing head.

As I'd like to have a reliable system i switched to Re