I have been working on my CNC controller enclosure while I await my CNC to be ready for pick up. I would greatly appreciate it if those with experience are willing to take the time to offer feedback on any aspect of what I have accomplished so far. I realized quickly from my research that opinions vary on what best practices to follow for, well, most everything to do with building one’s controller enclosure. What I have tried to do is incorporate those that made sense to me.
Note: I have extra wire in some places in case I change the component locations before my final install. Also, I have 3D printed temporary supports for a few things (e.g., power module, DB9 connectors, etc) to make my temporary mock-up easier/safer to wire.
Main equipment:
Power to the Masso G3 controller will be provided by one EDR-120-24 PSU
Power to other ‘to be added’ components – relays, sensors, contactors, etc - will be provided by a second EDR-120-24 PSU
Power to the Leadshine MX4660 driver will be provided by one SE-600-48 PSU
4 NEMA 23 stepper motors – 3.15V, 4.2 Amps, 0.75 Ohms, 3.0 mH

MX4660 driver wiring:
Power comes from the 48 VDC PSU through two pairs of POS+/NEG- wires into the two POS+/NEG- inputs
Stepper motor step/direction wiring follows that of the DB9 enclosure connectors: red=A+/green=A-/yellow=B+/blue=B-
I have ferrites on the step/direction wires from each motor
The DB9 black ground wires from the motors are connected to a set of five joined ground terminal blocks, which are connected back to the mains VAC ground terminal blocks
I temporarily have the MX4660 Estop+ and Estop- pins shorted with a wire loop until I decide how to connect them to the overall safety circuit
I have a DB25 cable connecting the MX4660 to a screw terminal breakout board for ease of wire connection. I also added a ferrite to this cable
I connected pi #25 on the breakout board to one of the shared common terminal blocks
MX4660 driver/stepper motor related suggestions/guidelines I tried to follow:
1. Do not exceed the voltage rating of the driver. I chose a 48VDC to stay below max rating of 60 VDC
2. Provide enough amperage for the motors. I chose 12 Amps which is over 2/3s of peak (12A / 4.2A X 4)
3. Provide common ground termination point for motors
4. Provide electrical ’noise’ protection using ferrites on motor/component signal wires
MX4660 driver/stepper motor related questions:
1. I already asked a question regarding how to wire the MX4660 estop with the Masso, and have it part of my safety circuit – thank you for those who responded. I have yet to decide what to do.
2. I have connected a wire from Pin #15 on the MX4660 which provides a 5V ‘Fault’ signal that can warn if any of the 4 driver modules are in protection mode (e.g.; over current/voltage). What is the best way to connect this to the Masso.
3. Could Pin #25 on the breakout board instead be connected to one of the Masso GND(G) inputs? The manual has it as I have done - to the Masso power supply (-) common.
Masso G3 wiring:
Power comes in from the dedicated 24VDC PSU. The POS+ wire connects through a 1 Amp fast blow fuse terminal block to one of the PWR+ inputs of the Masso.
The NEG- wire connects from one of the shared common terminals to one of the GND (G) inputs on the Masso
The Masso S+ step signal outputs for the X, Y, Z, and B axes are connected to pins 2, 4, 6, and 8 respectively on the BB9 breakout board
The Masso D+ direction signal outputs for the X, Y, Z, and B axes are connected to pins 3, 5, 7, and 9 respectively on the BB9 breakout board
*Pin #25 from the breakout board is already connected to a shared common terminal block
I have connected an Estop button using one available NC switch. The POS+ wire from the Masso PSU terminal block connects to one terminal of the NC Estop switch. There is then one wire that connects the other terminal of the Estop NC switch to the Masso ESTOP input Pin #2.
MX4660 driver/stepper motor related suggestions/guidelines I tried to follow:
1. Try to keep step/direction wiring short between the Masso and the MX4660 driver
2. Use the ‘B’ axis on the Masso for a CNC that uses a pair of Y axis motors
Masso G3 wiring related questions:
1. Is using one large ferrite core around all 8 step/direction wires, as effective as using four smaller ones around each pair of step/direction wires?
2. I have read numerous posts about this but just to confirm – Masso GND (G) Pins are actually common (NEG-) connections?