Dual Endstop X and Z

LowRider CNC Advice
1

I’ve been trying to figure out how to get a dual end stop LowRider working for the Z axis. I’ve verified each end stop is properly sensed, but haven’t figured out what changes to make in Marlin that will make it work. I’ve got a Ramps 1.4 board and started with the Dual end stop version (MPCNC_Ramps_T8_16T_LCD_32step_DualEndstop) from Ryan’s github. So far, I’ve changed:

in configuration.h:

Line 501: //#define USE_YMAX_PLUG // btm was not commented out Line 502: #define USE_ZMAX_PLUG // btm was commented out
Line 820: #define Z_HOME_DIR 1 // btm was -1
Line 834: #define Z_MAX_POS 92 // btm was 200
in configuration_adv.h (tried this with _ZMIN_ and _ZMAX_)
Line 316: #define Z2_USE_ENDSTOP _ZMIN_ // btm was _ZMAX_
Seems like the best I can do is to get the homing to stop only when ZMAX is triggered. ZMIN does not affect the homing once I changed the Z_HOME_DIR to 1.

Thoughts?

2

Z min is already in use, for Z1. Z max will be for Z2.

This will make you home to Z max, what good will that do? How will you know where the tip of the endmill is?

The LowRider has hard stops for both axis, what good is auto squaring going to do?

3

You’re homing to the positive Z direction, right?

Somebody had trouble with that here. IIRC, you can’t remap the zmax endstop, so you have to use zmax and ymax for the two z endstops.

4

Dang, learn something new everyday. I had no idea.

5

The zmax endstop actually seems pretty useful. You can home it up out of the way, get your work secured, then use zmin for a probe. I wonder where that other thread is. We went back and forth figuring it out… I remember it working too.

6

Can you use Zmin and remap the zprobe? How would you probe, we generally use Z home to trigger the touch, or is there another way?

7

Ummm. Good point. I was thinking there was a -Z home command… The probing can still happen, but I don’t think it will store it as zero. G30? G38?

8

Well, I’ll call that a learning experience and move on. I switched to the stock Ramps version without dual end stops. After testing it, I realized I needed to change the X & Y end stops to non-inverting since I was using them in a normally closed configuration. I left the Z as normally open so that I can use the touch plate technique. Thanks for the help and dose of thought. :wink:

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