My machine has a limit switch on the X and Y axis that is hit by a dog at each end of the table. There is also what I guess is a home switch that is slightly in from one of the limit dogs.
Should I uses the home switches at all? This is a VMC bed mill with tool changer.
My Z-axis is a whole other issue. There are two switches in series for the Z limits, but the top one is after the tool changing operation. The Z axis also has a home switch that designates the top of the "machining area". Above this tool changing occurs.
So, how should I wire this? Should I just rely on Mach 3 and a soft home limit for this home position, or try to use the switch somehow?
There are also 2 other switches above the home position and before the top limit switch as follows:
-A N/O switch that gets closed anytime the Z axis goes above the home and into the tool change area.
-An N/C switch that opens when the Z has gone up far enought to change the tool.
Here is a visualization of what occurs on the Z axis.
--- Over travel limit switch
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--- Tool Change Zero switch (should never really go past this)
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| Rotate To next tool
| Tool change occurs in this zone of z-axis movement
| Drop Turret
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| Release draw bar
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--- Tool change area switch is closed above this and stay closed until it comes back down past
--- Home limit switch
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| Machining area of Z axis
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---Over travel limit switch
I realize I am going to have to do some sort of macro for the tool change, but how should I wire this and which switches should I actually use? There are a couple risks. One is that you don't want the spindle motor to be on during the tool change area. Also, I am not positive yet, but damage may occur to the tool change rod that rotates the the turret if you go past the tool change zero switch.
I am drawing the schematics for the machine now, and the last thing I need to figure out is the wiring of all these switches.
See attachment for a visualization of the switches. You can also read my post on determining if I needed a PLC or not here:
http://www.machsupport.com/forum/index.php/topic,17091.0.htmlI have determined that a macro should do, but I don't know how to do it yet. Right now I just want to get it wired correctly.
Thanks