Was about to get a toy- then I did some research...

[JAZZCNC]

but the basic supply to the drivers can be pretty crude by comparison. In fact, a simple linear power supply will beat the pants off a switched-mode supply when it comes to feeding stepper drivers as you have to drastically over-spec the SMPS to cope with the odd peak load which causes it to go into shutdown or some other protective mode where the linear supply just dips a bit and carries on.

Neale is 100% spot on and using an SMPS is asking for trouble because at some point it will bite you when it goes into protection mode. KISS works for CNC no need for over complicating the job with Surge protectors or UPS, DHL, FedEx or any other courier service...

Now back to these drives and the Question of AC or DC. I've used these drives with both AC & DC and in terms of performance, I've seen no differences.
However, I've never run them on machines working in harsh conditions regards power fluctuations, etc but I suspect that if the mains supply was prone to fluctuations or was a little dirty then using a DC supply would be less stressful on the drives due to larger Caps being more capable of smoothing out the power than the little caps that will be used on the individual drives.

Now I'm not into electronics so I don't know if when using a DC supply the drives still use their onboard Caps as extra smoothing.? . . my gut says they probably do.!

But that said I would always go with the simple approach if normal conditions so AC is easier and cheaper. The machine doesn't care if you run it on Everyready battery's so long as it gets a nice supply of power when it asks for it.

[Kitwn]

Now I'm not into electronics so I don't know if when using a DC supply the drives still use their onboard Caps as extra smoothing.? . . my gut says they probably do.!

If they use the same input connections for DC as AC as I assume they do then the rectifier and capacitors must still be in the circuit.

One other thing to consider: If you add an additional rectifier and capacitors to make a DC supply for an AC driver you will also increase the inrush current to the transformer and increase the risk of trips. Adding more capacitance for the sake of it to any DC supply (making Neale's audio amp PSU instead of a motor driver one) will have the same effect.

[NeoMorph]

If they use the same input connections for DC as AC as I assume they do then the rectifier and capacitors must still be in the circuit.

One other thing to consider: If you add an additional rectifier and capacitors to make a DC supply for an AC driver you will also increase the inrush current to the transformer and increase the risk of trips. Adding more capacitance for the sake of it to any DC supply (making Neale's audio amp PSU instead of a motor driver one) will have the same effect.

Yup. My brain was in full “doped up on morphine mode”... which is why I did a facepalm. It’s the reason I had to quit work. Not asking for sympathy, just stating the way things are. I seriously do not know this tech, BUT I WANT TO LEARN. It’s better to ask questions and act a fool than profess to be an expert and tell people incorrect info because “Well it works for me so must be okay”. A lot of my expertise is 20 years out of date and worked with super delicate security systems that required strong, stable power sources to detect intrusions. These days you could build the same thing for lest than 50p with tech from Asia.

But I love making things which is why I got into CNC in the first place. Anyhoo... I’m going to shut up until I can reduce my meds come spring.