Power supply question

Hi all,

I know this has been talked about to dead, however I can't find a good arguement either way. Do I go with a pc power suppy or a no-name 12v 30a 320w supply (like this example supply). This is for my first printer (prusa i3, 5x nema 17 motors, ramps 1.4, and pcb heatbed). I need to buy the supply as I don't have any spare of either type around. My concern about the no-name version is saftey (read fire haszard) and reading to put in a regualtor circuit if I need a 3.3v rail for something that the arduino can't source. Let me know your thoughts. Thanks.

I had an old 400W ATX power supply sitting around which I tried using for my Prusa i3 with PCB heated bed. Since it claimed to supply 20A on the 12V rails, I thought it should be able to handle the required current.

I was wrong. It could not heat both the bed and nozzle. It took me way too long to figure this out.

I ended up getting an Antec Basiq 500W power supply.

My conclusion is that no-name power supplies often cut corners on the high-current 12V rails. The Antec 500W power supply is around $50 at Fry's.

Personally, I'm using an old "broken" PC power supply because it was something I had lying around. If I had to buy one though, I'd get the one you linked to since it looks like it would work great. As far as safety is concerned, the machine you're building is probably more of a concern than the power supply.

I own 2 of the no-name 30 amp units and have not had an issue with either.

I had an issue with one, but it was because I accidentally unscrewed a heatsink

I ended up buying one of these: Meanwell 12v 320A power supply

Decided to spend a little more than on the Chinese knockoffs as who knows what the ripple on them is and I've had psu's take entire systems with them.

ok well I just got a 24v supply from amazon, oddly there was a loose screw inside, which i replaced. other than that its perfect, it really makes the motors run smoothly, much better than the 12v. I believe everyone uses 12v only because of the atx psu's, which are total crap at regulating voltage btw. another thing is i can boost this sucker up to 30 volts if I need to, and run the motors even faster.

Can you please link to your Power supply on Amazon?

What electronics you running?

Running hotbed at 24V? If, so which one?

thanks.

[www.amazon.com]

Im running my bed on my 12v 30a psu, its 12x12 and uses about 270 watts, I recently etched it from a 12x12pcb. my electronics are megatronics 2.0. now one interesting thing is the mosfets for the bed and hot end and fans switch only the ground, so if you attach only the ground to the outputs on the board, you can attach the positive side directly to the positive rail of your power supply. this allows you to use basically any voltage parts and still control them with the electronics.