Desktop size steel welded router 3 axis

[Tom J]

Ok. Jazz
I know what you mean by using one sensor:

So far I use 2 sensors, one is limit +, other is Home and limit- all in one, connected like that:

I think this is your option#3 " uses 2 inputs and 2 types of switch. NC wired in series for limits on one input. NO wired in parallel for Homes on other input"
I was wonder how you get away with having only one sensor, must use soft limits in Mach for safety. I've seen 3 sensors solution: limit+ limit- and home in one axis, but I think is not needed.
Correct me pls. if we I am wrong.

[JAZZCNC]

I think this is your option#3 " uses 2 inputs and 2 types of switch. NC wired in series for limits on one input. NO wired in parallel for Homes on other input"

Well kind of but your way is a bit mixed up because the (+) Limit is NC but the (-) limit along with Home are NO so doesn't have the safety on the (-) limit side if wire breaks.!

If you used all limits with NC wired in series on one input and homes with NO wired in parallel then you'll be safer.

I was wonder how you get away with having only one sensor, must use soft limits in Mach for safety. I've seen 3 sensors solution: limit+ limit- and home in one axis, but I think is not needed.
Correct me pls. if we I am wrong.

No Softlimits are optional and not required you still have Limit switch safety.
Maybe what your not realising is that Mach only Watches Limit Inputs when working and ONLY watches Home Inputs When Homing and Ignores Limits while doing so. It also by default Moves one axis at a time so only looking for one Input to change state. If all set to same Pin # then any will do for mach.

This is why you can share one input for ALL axis homes & limits provided they use NO switches. Mach doesn't know or care which Switch triggered it just responds to the trip.
So if cutting it see's this trip and knows it's a Limit so E-stops.
If it's homing then it knows the Axis it's moving and when see's Home Input change state it sets the Home position for that Axis. Then moves onto next Axis and does the same. It doesn't care which switch tripped so in practice you can actually set say the X axis Home by triggering the Z or Y axis switch.!

The ONLY time it won't work is if you have changed the HOMING sequence so 2 or more Axis home at same time. In this case you need separate Home inputs for each axis.

[Tom J]

This is why you can share one input for ALL axis homes & limits provided they use NO switches. Mach doesn't know or care which Switch triggered it just responds to the trip.

Got it, but not quite to the end. How than having NO switch will provide safety on the limit side if wire breaks?

[JAZZCNC]

Got it, but not quite to the end. How than having NO switch will provide safety on the limit side if wire breaks?

You can't have continuity safety with NO switches which I did say this in other post.

[Tom J]

Summarize, if I use TB6550 or similar BOB which has only 5 inputs: 1-X, 2-Y,3-Z,4-Limit/E-stop,5-GND than 3 switches used as home/limits detect the ground signal (NC-active low). Mach knows that this axis is in home position.
How should I wire if I use the same switch as Limit? Can not wire the same switch to pin 4 (limit/E-stop)
Using pin 4 will collide with homing (all switches will be in parallel - remaining two will have NC contact therefore no homing)
Jazz, could you please send the wiring - loosing plot.

[JAZZCNC]

Summarize, if I use TB6550 or similar BOB which has only 5 inputs: 1-X, 2-Y,3-Z,4-Limit/E-stop,5-GND than 3 switches used as home/limits detect the ground signal (NC-active low). Mach knows that this axis is in home position.
How should I wire if I use the same switch as Limit? Can not wire the same switch to pin 4 (limit/E-stop)
Using pin 4 will collide with homing (all switches will be in parallel - remaining two will have NC contact therefore no homing)
Jazz, could you please send the wiring - loosing plot.

You got me bambozzled now and Not quite sure what your asking for but here's quick diagram showing 2 options. Option #2 is probably your best option.

[cropwell]

Hi Jazz,

Here's a question for you - If you are using one switch for home and limit does Mach ignore the limit function while homing?

That leads on to another - If you have slaved motors on an axis does mach wind both motors until a home trips and then keeps winding the untripped screw until the other trips, thus squaring the gantry and then do the backing off the home switch to complete the homing and aligning process ? In which case I presume you would need to have separate inputs for each side of the machine.

I see the point of having 2 targets and one switch, I only recently realised that Mach took into account which axis was travelling and the direction of travel when homing. It makes sense of commoning inputs.

Cheers,

Rob