Wiring Diagram check

[cropwell]

So you're saying I should just have all switches as limits instead of separating homes / limits ?

Good to know :) I'm not sure what the difference is between PST relays and DP relays.

I just got inspired from your diagram, that's why I used relays on mine :) Or maybe DT relay it the other word for contactor ?


How about the limit/home switches ?

Normally a BoB has 5 inputs, which map to pins 10 to 13 and 15 on the port. They seem to be ususally used as Homes, Limits, E-stop and touch probe, leaving one spare. If you absolutely need more, you can always use a second BoB, which I do. That second board is very simple, just opto isolated inputs and outputs. It's overkill though

1. You have to keep Homes and Limits as separate inputs. Mach3 treats them differently, Limits are more like pressing E-stop in function. Homing is a different process, Mach moves the axis towards the Home position until the switch trips, it then jogs back until the switch reverts to normal. It does this for Z, Y and X in that order. Z first so your cutting tool is clear and high before the gantry moves.

2. ST on a relay or switch refers to 'Single Throw' which means your contacts either make or break.
DT means you have a common (COM) contact which makes with a normally open (NO) contact when the relay is energised and when not it falls back to the normally
closed (NC) contact.
This change over can be Make-before-Break but is normally (on a relay) Make-after-Break.
6P means 6 poles which is 6 sets of contacts inside the switch or relay. SP is usual for single pole, DP for double pole, after that numbers are used.

3. Contactors are special construction relays, suited to switching higher voltages without arcing, normally used for 3phase and suited to long 'on' periods.

C'mon G.E., I didn't guess.

Happy Holiday

Rob