48V Power supply

I couldn’t find any similar threads, so I thought I’d stick this out there in case it helps.

After my experience with the cheap 12V power supplies on my 3D printer that look like this:

I was not keen to use them on the MPCNC, I also wanted to get a 48V spindle and the main sticking point for that was to get a 48V power supply.

So after searching the web I found the RC model guys are converting secondhand server power supplies into battery chargers. Server power supplies get swapped before they fail so there’s a constant supply of the things on eBay which are way better at voltage regulation etc than the thing pictured above.

So I bought 4 Dell (650W) power supplies and made this:

All the 3D printed bits do is hold them together and put PC mesh fan filter over the air inlet end where the wiring also is.
The black thing on top is the 48V spindle controller.
I tap off 1 supply for the 12V for the controller and servo’s and all 4 for the spindle.
Instructions on how to do the conversion are in the links below:



In theory I now have a 3KW 48V power supply, in practice the wiring would not support that current and the house wiring would trip before then as well, so be sensible about it.

I used big auto spade connectors to go on the main power connections.
I used bread board jumpers to make the connectors for the little pins, which aviods having to solder them.
I used 10K trim pots to control the fan speeds, these were better than using a regular pot as they were too sensitive.

Also this is playing with mains voltage, it can KILL you, be very, very careful. If you do not understand the instructions in links, stop before you get fried.
These things have big capacitors in them, they stay charged for a long time after the thing is unplugged from the wall, they can kill, hurt, scare the poop out of you if you do something you shouldn’t to it, don’t assume its safe because you unplugged it.

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Man, I always knew you were a lunatic. :smiley: Nice job, but I won’t be touching this. :stuck_out_tongue: