Place 2 inductive sensors on the X-axis, one at each end, and use spanners to tighten them.
Use the custom gauge to make sure the sensors protrude from the steel parts at the correct length.
Next to each sensor, place a rubber bump and use 2 counter nuts to tighten it at the right distance, which protects the limit sensor if the carriage goes any further.
Fully tighten both using the third counter nut. so they don't get loose with vibrations.