LJ18A3-8-Z BY PNP NO still 8 mm sense range but the output is reversed so you need to set endstop inverting to 'true' for this one
and dissable the endstp pullup option

Quote
obewan
LJ18A3-8-Z BY PNP NO still 8 mm sense range

Thanks for the answer,
It's strange, because the different between the two sensors is obvious. With this sensor (LJ18A3-8-Z BY PNP NO blue tip) the distance from heatbed is less than the LJ18A3-8-Z BX PNP NO orange tip and the sensor is shorter. When I go home I'll make the comparison photo

Quote
obewan
but the output is reversed so you need to set endstop inverting to 'true' for this one
and dissable the endstp pullup option

I disabled the endstop pullup but I configured the endstop inverting to "false" because if I select "true" when the LED turns on the endstop status is: "open" and when the LED is off is "TRIGGERED", I don't know why.
This is my endstop configuration and the sensor works, finally

#define USE_XMIN_PLUG
#define USE_YMIN_PLUG
#define USE_ZMIN_PLUG
//#define USE_XMAX_PLUG
//#define USE_YMAX_PLUG
//#define USE_ZMAX_PLUG

// coarse Endstop Settings
#define ENDSTOPPULLUPS // Comment this out (using // at the start of the line) to disable the endstop pullup resistors

#if DISABLED(ENDSTOPPULLUPS)
  // fine endstop settings: Individual pullups. will be ignored if ENDSTOPPULLUPS is defined
  //#define ENDSTOPPULLUP_XMAX
  //#define ENDSTOPPULLUP_YMAX
  //#define ENDSTOPPULLUP_ZMAX
  //#define ENDSTOPPULLUP_XMIN
  //#define ENDSTOPPULLUP_YMIN
  //#define ENDSTOPPULLUP_ZMIN
  //#define ENDSTOPPULLUP_ZMIN_PROBE
#endif

// Mechanical endstop with COM to ground and NC to Signal uses "false" here (most common setup).
#define X_MIN_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
#define Y_MIN_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
#define Z_MIN_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
#define X_MAX_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
#define Y_MAX_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
#define Z_MAX_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.
#define Z_MIN_PROBE_ENDSTOP_INVERTING false // set to true to invert the logic of the endstop.

Edited 1 time(s). Last edit at 11/11/2016 05:13AM by dont_go_away.

If it weren't totally, ridiculously, incredibly unlikely, I'd say that perhaps your NPN sensor is wired with the wrong colour wires connected inside. Perhaps black is ground and blue is signal? I've never heard of this happening, but it's how it seems to be behaving.

Anyway I'm glad you're making progress with your PNP sensor.

In future, I retry to check the wires of the NPN sensor, I had never thought it would be a wires problem.
At the moment I will use PNP sensor that finally works .
Now I must resolve another problem, with the extruder, but I think that I will open a new topic .
Thanks again for your valuable advices!

Can you post pictures of the wiring scheme and the resistor?
I have the NPN sensor and I'm trying to figure it out how to wire it and where plug each cable.
I know I need to conect a resistor as well.

[mertarauh.com]

Run google search and use schematics with a voltage divider (2 resistors).

Quote
piper3d
Run google search and use schematics with a voltage divider (2 resistors).

Honestly, the one with the diode and resistor is safer. The schematic is linked to in the update on the bottom of the article that user 'paulorfo' has mentioned. I did the schematic myself a month or so ago and it works flawlessly and is very safe. Open the PDF file and check out the examples paulorfo, just do it in the way the doc says and it will be fine. Just remember to make a test case first, with the hardware setup to a normal power supply away form your machine to make sure you did everything right and measure the voltages with a multimeter.

---

http://www.marinusdebeer.nl/

Thanks, I'll try.
I've been reading a lot to understand the schematics and installation.
I'm totally dumb when it comes to eletronics....
I'm afraid to burn something. That's why I'm asking for clear instructions.
In any case I appreciate all the effort.