Benefit of 4th axis homing switch?

[deanq]

I currently don't have any homing or limit switches on my 8" rotary table. I've never needed one. I have seem some tables with homing switches. What am I "missing" that I could benefit by having a "home" switch on my rotary table?
If there is a good reason, what kind of setup (switch) is repeatable from two directions (or does homing in a circle only go one direction?)?
Dean

[ASC]

The best setup I know of is using a slitted disk with an optical switch.  When the slit is oriented over the optical switch, the switch changes state and gives your home pulse.  The axis will (and should) only home in one direction.  I do believe a rotary home switch is important if you have static fixtures on your rotary table, and also helpful in cutting threads.  The same setup can be used for a index pulse as well. 

[deanq]

The best setup I know of is using a slitted disk with an optical switch.  When the slit is oriented over the optical switch, the switch changes state and gives your home pulse.  The axis will (and should) only home in one direction.

Reasonable if only in one direction. Any switch could work?

I do believe a rotary home switch is important if you have static fixtures on your rotary table, and also helpful in cutting threads.

Wouldn't consider threading with a rotary table, I use a lathe or thread mill. What do you mean by static fixture? I keep a 4-jaw chuck on mine almost exclusively.
Thanks
Dean

[ASC]

On my rotary table I have a machined fixture that holds 3 pie-slice shape wedges for making airfoils for a dome shaped wind turbine.  The reference is at the center of the table but I need to start from the same point (home) each time I run the program or the cuts will be in the wrong place.

[BR549]

Unless you are doing fixturing on the 4th there is really little to gain from a Home switch. Most just set Zero to a reference point on the material and go. Same with XYZ

Just a thought, (;-) TP