Hi, when initially setting up, just make sure both gantry arms are the same distance from the frame, then when gantry is 'Homed', as each arm touches micro switch it stops that motor, so both arms end up in same position, (each motor runs indipendantly, being controlled by its own Hall sensor & Microswitch). This is can be seen on both the Stepcraft Video & the Joao Galego video on the Stepcraft Facebook Page
the hall sensors & circuit board keep track of spindle rotation, as each hall sensor is seeing the magnets in the motor coupling as they pass it, the electronics then adjust motor speed to keep both in synchronization, if one of the spindles goes out of synchronization, unit stops.
I think you need to check the wiring, as if wrong hall sensor connected to motor (ie, Y1 sensor to Y2 motor) it can not work properly, same aplies to the micro switches, also make sure each stepper is connected to correct terminals and wires are in the rigth colour sequence. (the new motors have different colouring and on the circuit board terminals run in different direction in terminal blocks if you start with RED).
Hall sensor connections to the circuit board can easily be connected the wrong way round, there is a temptation to have the plug the same way up on both sets of pins, but one has to be 'upside down' CHECK wire colours against the wiring diagram.
Each micro-switch and EM/Stop button use the two OUTER connections if any wire is connected to the middle connection the system will not work properly. Micro switch wiring (Black/White) do not have a colour preference so not a problem matching color to specific pin.
Using UCCNC and machine stops while running a toolpath (I run my spindle manually no computer connection for On/Off):-
Press EM/switch and release, then click Reset button, then using the RED buttons by 'Home All' individually send each axis home, 'Z', then 'X', then 'Y', this has put the gantry to 'Home' position and re-aligned each Gantry Arm.
Then by clicking 'CYCLE START' gantry will move to the stopped position and carry on.
IMPORTANT - firstly gantry will take shortest route, make sure nothing in the way as will not initially follow toolpath's, also if manually stopped spindle, re-start before cutter (Z axis drops).
To see how it works using UCCNC - run a simple toolpath in 'OFFLINE MODE' and stop machine using 'FEED HOLD', then follow above routine, you will see it work without actually moving the machine.
If gantry is moved to back frame and triggered the microswitches as both gantry arms need moving away from their switches, using 'OVERRIDE LIMITS' gantry can them be moved using UCCNC controls.
SC600/2, Kress 1050, UCCNC with UC100, Cut2D Pro, TurboCAD and Fusion 360