Need help in DIY configuration/design of Proximity Switches 5 Axis Rotary Axis

[Kobi see]

Hi,

Hoping someone could help with a newb question. I have been slowly working on a diy 5 Axis machine design for a number of years.
However I am stuck with how to setup proximity Switches on the fourth axis because it can rotate 360 degrees - but not continuously. In other words at zero position it is centered and can go either -180 degrees or +180 degrees. The issue is that there is only room for 1 proximity switch because a second switch would sit right on top of the first and that just can't work obviously. How is this functionality achieved on a commercial 5 axis gantry? Obviously if they use a slip ring they have no need for proximity Switches...I imagine that direct drive dc servos with encoders eliminates the need for proximity Switches. I have closed loop stepping motors but that isn't enough in the event of going over the 180 degrees. I have searched tirelessly and have found nothing online regarding this. Any help would be greatly appreciated!

Thanks
Kobi

[109jb]

If the travel is from -180 to +180, why not just put one homing switch at -180?? There is nothing to say that a homing switch has to be a "0"

[Kobi see]

Hi, thanks for your reply. Alright, I see your point but do cnc controllers and/or software like mach generally allow for a single proximity switch to do the job of 2 switches? Is one switch enough? Seems counterintuitive.