Do not use mechanical switches for HOME / ZERO switches. Use instead optical interrupters, they are much more repeatable and have less hysteresis than mechanical switches.

On industrial machines I worked on in the past we used optical type switches for the HOME, ZERO and MAX coordinate setting limits. Then we also added mechanical switches that would activate at a slightly wider range of motion that were used as the emergency disable switches to disable the drive motor before the movable axis hit the end stops.

Note it is common to wire mechanical limit/safety switches such that the negative direction switch would only disable motor motion in the negative direction. Likewise the positive direction switch would only disable the motor in the positive direction. This scheme allows the software to be able to still move the mechanism off the end stops for recovery.

Michael Karas