Z-Axis Gone Too Far

[ShawnM]

I was gonna say I've been using zero and my max travel limit value, either plus or minus, for years without any issues.

[RJS100]

I greatly appreciate all of the responses, but I am totally confused. My application is simple standard benchtop milling application.

Just to communicate the sensor locations:
There is one proximity sensor at the top of the Z axis to limit the maximum Z travel
There is one proximity sensor that I believe to be at the end of the positive X to stop the table from moving too far right.
There is one proximity sensor that I believe to be at the end of the positive Y axis to stop the table from moving too far to the rear of the machine.

My original configuration was as attached. The machine appeared to work properly. I got error messages when I attempted to exceed the machine envelope limits as expected. I ran the test Gcode a few times and it ran perfectly. On one day I ran it again and the Z axis exceeded the limit when a tool change was ordered. This is when I posted this question.

The previous posts indicate that I only setup homing limits and not soft limits. Can you please let me know how and where to setup these soft limits? The manual and the video posted are for different versions of CNC12.

Thanks again... Richard

[RJS100]

Oops. Just for clarity, here are the image of my X and Y axis proximity sensors.

[suntravel]

I was gonna say I've been using zero and my max travel limit value, either plus or minus, for years without any issues.

I also use 0 but with individual inputs for each axis with (Axis)HomeLimitOk and soft limits on the end with no sensor.

I thought 0 would only work as Limit on the end with a limit sensor...

Uwe

[Crosshatch]

I only have three mechanical switches on machine and also have the some "Zeros" for soft limits...

[ShawnM]

I also use 0 but with individual inputs for each axis with (Axis)HomeLimitOk and soft limits on the end with no sensor.

I thought 0 would only work as Limit on the end with a limit sensor...

Uwe

I just finished another router retrofit for my personal use, it's a Holz-Her machine to replace my last machine that I just sold. It has three NPN N/C proximity switches wired in series to a single input set to "HomeAll". No other limit switches on the machine. I have zero set as my travel limit minus for X and Y and zero set as travel limit plus for Z in the wizard under "homing and travel" (along with it's corresponding distance for my table) and it works every time with my soft limits. I get the axis travel limit messages as well.

[RJS100]

Thanks for your reply, Shawn. Some many months ago you sent me your wiring diagram for the NPN proximity switches. I wired them exactly as you mentioned below and am using zero for the travel limits just as you described. I ran a boat load of test Gcode today and have not been able to repeat the error I had when the Z-axis went too far (the reason I started this post).

I cannot be certain, but I think the reason Z-axis went too far may be a mechanical problem after all. I think the way guards (see attached) got tangled and blocked the proximity sensor. This is just my guess. Time will tell.

Thanks for all your thoughts.... Richard