Z-endstop reads 1 with no endstop installed

I bought my k40 used, and broken. I’ve replaced the power supply, laser tube, and control board. I’ve also rewired most of it. Additionally, my laser came with a light objects z-table.

I was having trouble with the z-table making noises and jerking back and forth, so I followed the z-table setup guide and was able to get the z-table to move very slowly. While troubleshooting my x and y endstops, I noticed that the z-endstop (which I don’t have) is reading 1.

I’m wondering if this could be part of my original z-table problem. I’m also wondering how it could be reading anything with nothing attached to a z-endstop.

Machine: k40, bought used and broken

Board: Laserboard

Firmware: _Smoothie

Problem/ Question: My used k40 came with a z-table (light objects, I think). I do not have a z-endstop, but when I run M119, I get the following results:

My home at 0, 0 is left rear. Xmin, Ymax, no z switch

“Here is the result of M119 when no switches are being depressed”

X_min:0 Y_max:0 Z_min:1 pins- (X)P1.24:0 (X)P1.25:1 (Y)P1.26:1 (Y)P1.27:0 (Z)P1.28:1 (Z)P1.29:

“Here is the result of M119 when the x min switch is being depressed”

X_min:1 Y_max:0 Z_min:1 pins- (X)P1.24:1 (X)P1.25:1 (Y)P1.26:1 (Y)P1.27:0 (Z)P1.28:1 (Z)P1.29:1

“Here is the result of M119 when the Y max switch is being depressed”

X_min:0 Y_max:1 Z_min:1 pins- (X)P1.24:0 (X)P1.25:1 (Y)P1.26:1 (Y)P1.27:1 (Z)P1.28:1 (Z)P1.29:1

Did you provide those pictures? We need pictures to understand your setup!

I’ve not setup a Z axis but have you checked the config.txt to see if the Z axis is enabled and therefore it’s showing the default z endstop position?

Please provide pictures of your board, machine, and wiring so we can have a look In particular we would also need to see where you have the Z endstops hooked up, and how you have the config file set up to match all that.

Micro controllers and other processors often are designed with internal pull up and/or pull down resistors on I/O(input/output) pins and these can be controlled in software. So it is not really uncommon for a pin with nothing connected to it to be stuck at 1 or stuck at 0.

What I would look for is a way to disable the Z endstop homing and maybe it will disregarding the Z endstop signal level all together.

Based on other threads I’ve seen on this forum, I expected the Laserboard to default to 0 for the x, y, and z endstops. Is that not the case? @DOugL, what you are saying makes sense for microcontrollers and processors in general. I’m wondering if the Laserboard is subject to the same propensity for pins getting stuck at 1.

@Cohesion3D, if I don’t have any Z endstops hooked up, do you still need pictures?

Have you shorted the Z endstop SIG pin to the Z endstop GND pin and tested? Or just move one of the X or Y endstops to the Z endstop position and run the gcode test and show the changing Z endstop.

If your X and Y endstops are connected to the NC connections of the endstop switches then they could show 0 while Z shows 1…

I overlooked that bit originally. I don’t think that the lack of z endstops is related to your issues. The home button in LightBurn should only home the X and Y axes.

You can disable the endstops for Z by setting those pins to nc in config, but as I said, it should not make a difference.

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