Homing and end stop switches
any recommendations on switches to use for homing switches and end stops. I use a lot of proximity switches on the packaging machines we build, but they are all NO and when they detect a flag made out of a piece of metal they turn on. It appears most 3D printers use regular micro switches. Homing switches be wired NO and turn on when the axis is homed, or NC and turn off when the axis is homed.
3D Printing has a strong community heritage of being very, uh... "inexpensive"... Ok, CHEAP. Microswitches are dirt cheap and work very, very, very well.
Also consider: The homing switches really don't need to be that accurate on a 3D printer. Unlike CNC, where there may be fixtures, or a rough cut followed by a tool change and a finish cut, etc, etc. 3D printers generally print well away from their limits, and mostly do not re-calibrate.
There are some exceptions: Delta Printers, depending on how Z-Probing is used, may need quite a bit of repeatability in homing switches. Occasionaly, prints are re-started, etc. So don't take any of that as absolute... but... mostly... homing switches just don't really matter that much.
Summary: Micro-Switches are cheap, reliable, and more than up to the task.
Having said that, if you have a box full of sensors and could wire one in your sleep... go for it, man!