Power supply cooked; what's the right kind?

[brebey]

Hi all, and thanks for your help.

I just got my home-brew CNC router working, got Mach 3 all set up, got the home/limit switches all working, soft limits set, and the whole 9 yards. Everything was working perfectly. I finally took the plunge into clamping down a workpiece and was going to make my first live cut (the Roadrunner carving that comes with Mach 3). I hit homed the motors one last time, and to my surprise, even thought the DROs were counting, the motors didn't turn.

This went on for maybe two or three seconds - just long enough for me to take stock of what was happening - and then the GFI on the circuit that everything was plugged into tripped, and everything shut down. Resetting the GFI brought the PC back up, but the CNC power supply was dead. Now it won't even power up on its own (with no controller attached). The fuse is fine.

Does this ring a bell with anyone? What might have happened? Everything was working fine before the "crash".

The supply was an eBay deal (or not so much of a deal?), branded "Mean Well S-145-24, Output 24V, 6A".

The motors are a no-label stepper touted as 500in/oz 1.8 degree motors. The worked perfectly (albeit slowly) until the failure (I am only able to operate them at about 22 in/min; they stall faster than that).

Did I have a power supply mismatch? Did I just get a lemon? Is there a better fit?

Also, is there anything I can do to make the motors go faster without stalling? More current? More voltage? None of the above? All of the above?

Thanks for your help - I'm frustrated and a bit lost.

[NC Cams]

Short of finding something EXACTLY engineered to fit your combo, you need to find something that you can adapt that has reasonable "robustness".

It is relatively easy to "daisy chain" (stack them in series) AT power supplies to achieve any practical voltage. In your case, 24-25 volts is pretty easy - stack up several of the 5vdc outputs AFTER properly modifying the grounding scheme to prevent shorting as you daisy chain them.

How to do the grounding modifications: do a "ower supply daisychain" or "AT power supply" search on the "Zone - there have been NUMEROUS references/links posted on how to do/where to find and several are VERY well illustrated - even the most innept non-electronics person should be able to do the mods.

The "Zone also has had numerous replies on how to size and select the operating voltage for the typical stepper. Again, the 'Zone's search engine is your friend - use it to good advantage.