Sumtor Control Board - homing/limit switches

[Roy-J]

I think it would be simpler and easier for me to stick with micro switches.

So that I am clear on this the connections would be made as follows?

2 micro switches for the X axis into IN2 (already occupied by the emergency stop switch)
2 micro switches for the Y axis into IN3
2 micro switches for the Z axis into IN4
All configured in Mach 3

Sorry if I am confusing the matter it's just electronics are not my strong point here.

Regards

Roy

[Clive S]

I think it would be simpler and easier for me to stick with micro switches.

So that I am clear on this the connections would be made as follows?

2 micro switches for the X axis into IN2 (already occupied by the emergency stop switch)
2 micro switches for the Y axis into IN3
2 micro switches for the Z axis into IN4
All configured in Mach 3

Sorry if I am confusing the matter it's just electronics are not my strong point here.

Regards

Roy

I would wait for a little longer and see if one of the electronic guys show up.

It might be possible to connect the three home switches to one input.

https://www.machsupport.com/forum/in...?topic=31845.0

edit: It would be good to quote the other names next to the inputs as the cable is obscuring them

[JAZZCNC]

Hi Roy,

You can do this several ways, ranging from using just 1 input and 3 switches(4 if twin motors) or upto 10 switches with each axis using 3 inputs.!!

In your case the best option would be to use just 2 inputs. One for the limits and one for the Homes. Use separate switches for Homes and Limits.
I would Leave the E-stop on it's own Input and use separate for limits/homes.

The Limits you would wire all the switches in series using NC (normally closed) switches. Series meaning the first switch connects to the second and so on like a daisy chain. This way if any one switch gets tripped the circuit is broken and Mach3 see's the trip.

The Home switches you will wire in parallel, meaning each switch goes to the one Input.

You can do this because when Mach3 Homes it only moves one axis at a time and it doesn't care which Input it see's triggered, it just watches the Input it's told to watch.
So you set each Axis to watch the same Input when homing. So when for instance your homing X axis you could actually trip the Y axis switch and Mach3 will think it's the X axis Home postion that tripped because that's the axis it was moving.

Obviously if you wanted you could assign a separate input to each Axis and Home all of the axis at same time, but by default Mach3 only moves one axis at a time, starting with Z, then Y and X, so the above works. To move all 3 at same time would require a tweak to a file in Mach3 and it's also wasteful of Inputs.

There is one last option which uses just one input and one switch on each axis for both Limits and Homes.

To do this you have the switch travel with the axis and at each end of travel you have a target the trips the switch. The switch will also need to NO type so the Homes will work.
The down side to this being the NO switch isn't has safe for the limits because if a wire breaks or the switch gets damaged you won't know about it until it doesn't work when hit. Using NC type for limits is much safer. Hence why I would use two inputs with NC Limits and NO Homes.

Edit:

Another option is to only fit HOME switch and set Softlimts within Mach3. Softlimits will keep you from crashing the machine provided you HOME the machine when first turned on.
To be honest even if you have LIMIT swithces fitted I would set Softlimits as they won't allow you to crash the machine, even if you deliberatley tried to crash it they won't let you and bring the machine to a nice controlled stop when comes to end of travel. Mach3 also checks the G-code and warns you if the code exceeds the Softlimits.