Need Help!- Combined home and limit switches driving me nuts!

[adbradley]

I am setting up a denford orac lathe with a new controller and Mach3, but for the life of me, i cant figure out how to set up the home switches and limit switches to share one pin.

I have a limit switch on the x, and one on the z, they are NC, and they are wired in seriese. They work just fine as limit switches on pin 11, but i want to use them as home switches as well. When I turn homing on to pin 11, and try to home an axis, it his the switch, then gives me a limit switch error, and has to be reset.

I have read through the mach turn manual a few times, but just cant figure this out. Anyone have any idea what im doing wrong??

Thanx
Adam

[TOTALLYRC]

Originally Posted by adbradley I am setting up a denford orac lathe with a new controller and Mach3, but for the life of me, i cant figure out how to set up the home switches and limit switches to share one pin. I have a limit switch on the x, and one on the z, they are NC, and they are wired in seriese. They work just fine as limit switches on pin 11, but i want to use them as home switches as well. When I turn homing on to pin 11, and try to home an axis, it his the switch, then gives me a limit switch error, and has to be reset. I have read through the mach turn manual a few times, but just cant figure this out. Anyone have any idea what im doing wrong?? Thanx Adam

Here is what the manual says.
When using home and limits together I am not sure if you can tie all the axis together. Try just the x axis and don't series with the z and see if it works. Then you could do the z on another pin.

Mike

"If you implemented configuration two from Section 4.5, you will probably have Home switches on
the X, Y, and Z axes. Enable the Home switches boxes for these axes, and define the Port/Pin to
which each is connected. If you are combining limits and the Home switch as one signal, then you
should enable Limit --, Limit ++, and Home for each axis and allocate the same pin to Home,
Limit --, and Limit ++."

[adbradley]

I have tried that, with no luck. It is still interpreting it as a limit switch and stops the machine.

[adbradley]

im sure im missing something simple

[ger21]

Did you restart mach3 after setting up the home switch pins?

[adbradley]

Originally Posted by ger21 Did you restart mach3 after setting up the home switch pins?

Yes i did, i just read of a similar problem on the artsoft's forums, they solved there issue by changing the debouncing to 2000, so im going to try that

[Runner4404spd]

THe home pins cannot be tied together. the limit switch pins yes. when homing mach does each axis indepently so if one finishes homing before the other it will stop there. on my lathe you have an x high and and x low limit, you also have a z high and a z low limit. you can use either of the swithes as both a limit and a home but you will still need to use a minimum of 3 input pins. 1 for the joint limit, 1 for x axis home/limit and 1 for z axis home/limit.

hope this is clear.

[adbradley]

i will change my setup then, thanx runner4404

[pminmo]

Maybe this might help some in the future: http://pminmo.com/home-and-limit-switches

[mecheng10]

I have my 3-axis cnc mill set up to run the shared limit/home switches on all three axes from a single pin and it works fine on my machine so I know it can be done. When you set all the limits and home signals to the same pin Mach 3 is smart enough to know how to interpret the signal based on the context of the machine at a particular time. The only drawback I have found using this method is that the axes have to be homed sequentially (one at a time) which takes a little longer.

-Brian

[Fastest1]

Mech, the way I understood it you could do exactly what you are doing. I think and or I am hoping that I can even do that with only 1 limit switch on each axis. If I remember right you tell it which way to travel to find the limit switch and then it backs off a preset amount that you specified and as you say 1 axis at a time til all are homed. 1 axis at a time is better than losing position and having to start over at square one!.

Originally Posted by mecheng10 I have my 3-axis cnc mill set up to run the shared limit/home switches on all three axes from a single pin and it works fine on my machine so I know it can be done. When you set all the limits and home signals to the same pin Mach 3 is smart enough to know how to interpret the signal based on the context of the machine at a particular time. The only drawback I have found using this method is that the axes have to be homed sequentially (one at a time) which takes a little longer. -Brian