End Stop MAX doesn't work but MIN does

Mostly Printed CNC - MPCNC Troubleshooting
#1

I purchased everything from here.

I found out using a multimeter that the board likes NO (I think I saw in the firmware that the logic was inverted" Makes no difference since it just has to cut the circuit.

For X and Y (didn’t test Z yet) end stops, the MIN works just as expected. The minute I press down on the endstop (wired as NO) the motors stop. But for X or Y MAX, it doesn’t work. Just to test, I wired the MAX as NC and still nothing.

You can see from this picture what I’m talking about. I wired the top pin as Signal and the middle pin as GND. I ruled out the stoppers or cabling because if I take a known-good XMin setup and plug it into X or Y MAX pin, it doesn’t work. Conversely, if I take the endstop/wires from the X or Y MAX (which doesn’t work) and plug it into M or Y MIN, it works just fine.

What am I doing wrong?

TY

end stop min/max
HV4kEcN.png1168×979

#2

You will need to enable the max endstops in the firmware.

#3

LOL. That was easy enough. I saw a post by you that said “I disabled it in mine” but I figured you were talking about physical, not in FW.

I can just grab this one: B16_32-LCD-112515 since I’m not using an LCD screen?

Thank you

#4

No, use the RC7 build. You can easily disable the screen.

#5

Hmm, OK, I got the RC7 image, and just added the missing u8glib. There were too many dependencies in LCD libraries to just comment out the #include u8glib.

I also changed the true to false for #define X_MIN_ENDSTOP_INVERTING. So I can use the NC instead of NO.

But then I got to thinking, why don’t people use X_MAX. Maybe my thinking is wrong? I was thinking that X_min is one side of the axis, and X_max is the other side of the axis. I get that X_min and Y_min are used for homing. But no one uses X/Y_MAX just as insurance?

Am I missing something more fundamental?

Hansang

#6

Just comment out the include lcd and the u8glib dependency goes away. search mpcnc in the config.h and you will see where I uncommented the reprap lcd you just need to add the “//” back in. I will update all this when the firmware dev stabilizes again.

My suggestion has always been if you really want spend the time to use endstops you should use min and max.

#7

Thank you so much! I’ll look at the LCD part once more.

Hansang