Thomas reviews 12 different bed leveling sensors

Herr Sanladerer performed a serious testing run with 12 automobiling sensors and made a video with the results.

Tested sensors were:

• M8, 2mm inductive sensor (5V)
• M12, 4mm inductive sensor 
• M16, 8mm inductive sensor 
• M16, adjustable distance capacitive sensor 
• M16, 20mm capacitive sensor 
• David Crocker's IR sensor 
• SHARP analog sensor 
• Microswiches 
• BLTouch 

Here is the testing video:




The conclusions were:

• If you have an aluminum bed, I'd go for the 2mm inductive type
• For a glass-only bed, the BLTouch is a good option
• With a PEI sheet or other stick-on bed surface, David Crocker's differential IR sensor is also a great alternative
• The capacitive sensors are too sensitive to use seriously, and the SHARP type is not precise enough. 
• Inductive sensors with larger trigger distances also work really well, but will need circuitry for adapting to 5V and are much larger than the 2mm type.

Detailed report with many interesting details can be found at:

https://toms3d.org/2017/03/02/autoleveling-3d-printers-9-myths-12-sensors-tested/

cOssel delta 3d printer by Chris Dieringer

cOssel is a Rostock / Kossel derivative by Chris Dieringer. It does a few things differently from other deltas, still the central design and technology is the same. Main features are:

• OpenRail for linear motion 
• Dual hot end configuration 
• Bowden extruder designed for geared steppers 
• Mechanically fixed heated bed, vs. binder clips
• cOssel attempts to enable a low-power, non-contact automatic leveling sensor as an alternative to using a retractable mechanical switch as used in other deltas. This feature is still experimental as most IR sensors have not been proven repeatable.

cOssel has dual reflective IR auto leveling,  This feature is still experimental as most IR sensors have not been proven repeatable.





You can build it yourself, all files and instructions are available at:

http://reprap.org/wiki/COssel

https://github.com/cdaringe/cOssel

http://www.thingiverse.com/thing:244893

cOssel IR leveling sensor (still experimental)