need help with limits and home switches

[eloid]

I have a question regarding home switches....
where should the home switch be relative to the limit switch ie in the y axis..
should it be set the same distance back as the y axis limit ?
If I have a travel arm mounted on the carrage it should hit limit switch frist
swip past it ie...have a small travel distance till it hits y home switch.....?




H---L -y axis ..........................+yaxis L
^
^^{carrage mounted arm}---------------------

please post a picture,,, if you can of your set up...

[pminmo]

It partially depends on the control software and if you are using steppers or servo's. For steppers, personally I put one switch on each axis, a "Home" switch. For the Z axis I place it at the up end of the travel. On the X (and Y) I place it on the end of the axis where I want 0.0. MACH3 and EMC you can define software limits that once "HOMED" minimizes the need for actual hardware "Limit" switches. EMC you can define that "HOME" switch also as a limit switch for that end of travel. But when you set it up, you have to move away from the "HOME" switch during a HOME operation.

[ger21]

Limit should be outside the home switch. The machine can't pass over a limit to get to home, as the limit switch will stop the machine before it can home.

[Bubba]

In my case, I use the home switch as the limit switch! In other words, the same switch is used for a dual purpose! In this case, the limit position is basically the home position. It saves space as I only had to have one switch to do the job and most controllers that I am familiar with will allow this practice.

[eloid]

Originally Posted by ger21 Limit should be outside the home switch. The machine can't pass over a limit to get to home, as the limit switch will stop the machine before it can home.

ok so the home switch can be triggered befor it hits my -y limit switch
as shown below

L -y axis ......H.......................L +y axis
................^
.............. ^^{carrage mounted arm}---------------------