Folger Tech Prusia i3 Build - Z Axis End Stop Not Functioning

Last night I got everything built and wired up. I installed the recommended software and firmware for the printer from the Folger Tech google drive. I connected up to the printer through Repetier and homed the X and Y axis. Both worked fine. When I went to home the Z axis, the end stop did not trigger the Ramps 1.4 board to stop the steppers although it was pressed. I verified the correct pins on the Ramps 1.4 board were used, all good. I swapped out the Z and X end stop to see if it was a bad end stop. When I held down the X end stop and homed the Z axis, it still did not stop the steppers. That led me to believe I either have a problem with the Ramps 1.4 board or the code. I opened up the code and all endstops are set to function at min values, which is correct, the Z axis end stop is at the bottom of the Z axis.

Does anyone have any idea what's going on? Any experience with this type of problem? Everything else works just fine. Bed heats up, hot end heats up, thermisters are reading correctly, X and Y axis fine. Just this Z axis issue! So close to printing!

Also, it's interesting to note that the X end stop LED lights up when it is triggered. The Y end stop LED DOES NOT light up when triggered but it still works to stop the Y axis from continuing past home. The Z end stop LED also DOES NOT light up when triggered, even when swapped with a different port on the RAMPS board. Not sure what's causing that either...

Thanks for you help!

Please let me know how your end stops are installed:

X on left or right of axis?
Y on front of back of axis?
Z on top of bottom of axis?

(A couple photos would be most helpful, including one of the connection to the RAMPS board.)

Also, please post your Configuration.h file from Marlin.

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-David

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I've attached photos of the end stop locations on my printer, hookup location on RAMPS, and the configuration.h file I used.

Thanks for looking at this for me!

Your X and Y end stops are installed in the MAX locations, but plugged into the RAMPS board as MIN end stops. You'll need to move the plugs up one space, but leave the Z end top plugged in where it is.

Also, change the following in your Configuration.h file:

#ifndef ENDSTOPPULLUPS
  // fine Enstop settings: Individual Pullups. will be ignord if ENDSTOPPULLUPS is defined
  #define ENDSTOPPULLUP_XMAX
  #define ENDSTOPPULLUP_YMAX
  #define ENDSTOPPULLUP_ZMAX
  #define ENDSTOPPULLUP_XMIN
  #define ENDSTOPPULLUP_YMIN
  //#define ENDSTOPPULLUP_ZMIN
#endif

#ifdef ENDSTOPPULLUPS
//  #define ENDSTOPPULLUP_XMAX
//  #define ENDSTOPPULLUP_YMAX
//  #define ENDSTOPPULLUP_ZMAX
  #define ENDSTOPPULLUP_XMIN
  #define ENDSTOPPULLUP_YMIN
  #define ENDSTOPPULLUP_ZMIN
#endif

to

#ifndef ENDSTOPPULLUPS
  // fine Enstop settings: Individual Pullups. will be ignord if ENDSTOPPULLUPS is defined
  #define ENDSTOPPULLUP_XMAX
  #define ENDSTOPPULLUP_YMAX
  #define ENDSTOPPULLUP_ZMAX
  #define ENDSTOPPULLUP_XMIN
  #define ENDSTOPPULLUP_YMIN
  #define ENDSTOPPULLUP_ZMIN
#endif

#ifdef ENDSTOPPULLUPS
  #define ENDSTOPPULLUP_XMAX
  #define ENDSTOPPULLUP_YMAX
  #define ENDSTOPPULLUP_ZMAX
  #define ENDSTOPPULLUP_XMIN
  #define ENDSTOPPULLUP_YMIN
  #define ENDSTOPPULLUP_ZMIN
#endif

and change

// ENDSTOP SETTINGS:
// Sets direction of endstops when homing; 1=MAX, -1=MIN
#define X_HOME_DIR -1
#define Y_HOME_DIR -1
#define Z_HOME_DIR -1

to

// ENDSTOP SETTINGS:
// Sets direction of endstops when homing; 1=MAX, -1=MIN
#define X_HOME_DIR 1
#define Y_HOME_DIR 1
#define Z_HOME_DIR -1

---

-David

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Hey David, Thanks for the reply. I tried your code modifications out and I still had trouble. I ran M119 with no switches contacted and got all open. When I pressed the X switch, Xmax was triggered (because of the changes in the code). When I pressed the Y, same thing, Ymax was triggered. The Z axis however, still did not trigger no matter the state of the end stop switch.

I did some more digging with a multimeter on just the Z endstop AND the cable. After the end stop functioned perfectly, I started testing the wires. The red and green were fine but the black wire showed a resistance of 156k Ohms.... So that was the culprit. The black wire must have had a break inside the insulation because the terminals looked like they had great connection. I swapped out the wire and it's homing correctly.

Now about the code. The Y axis functions like I want it to. I would like it to home towards the front so when a print is done it brings it forward. The controls for the X are backwards when using Repetier. When I hit -10 it goes to the right, +10 it goes to the left. I'm assuming I just have to mess around with those variables to get it going the directions I want. Now if I wanted to reverse that, would that mess around with anything I try to print? Like will it print something flipped? I'm assuming it will.

You can switch the direction of the X-axis (or any of them) in this section, but changing true/false:

#define INVERT_X_DIR true    // for Mendel set to false, for Orca set to true
#define INVERT_Y_DIR false    // for Mendel set to true, for Orca set to false
#define INVERT_Z_DIR true     // for Mendel set to false, for Orca set to true
#define INVERT_E0_DIR false   // for direct drive extruder v9 set to true, for geared extruder set to false
#define INVERT_E1_DIR false    // for direct drive extruder v9 set to true, for geared extruder set to false
#define INVERT_E2_DIR false   // for direct drive extruder v9 set to true, for geared extruder set to false

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-David

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Thank you!

MindRealm! I LOVE YOU! this solution helped me fix my similar problem. Thanks so much!

I have the same problem but the endstop works, checked with M119 and shows open or triggered when I press the switch but will not stop the z-axis.

I used the code above and I removed the comments but now when I type g29 the extruder goes outside the bed.....

slanwar,

Happy to help. Send me a PM and I'll help set it up. [SEND PM]

-MindRealm

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-David

Find me online at:
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Check out my FolgerTech Prusa i3 (plexi) at MindRealm.net