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I'm still waiting to receive my Rostock V2 and found a 500W PC power supply in my father's home. Will the slight bump from the stock 450W PS to this new 500W make any noticeable difference? Ideally if would take less to reach temperature or at the very least and allow me to install some custom LED lighting without loosing any performance. Any thought on this?

Leds will not consume a significant amount

As for the 500w issue. Some say the original psu is not fit for purpose but still, you will not gain much by installing a different if the voltages are the same.

What would be beneficial is if you add say thicker wires going to your heated bed.


Adding a psu with higher voltages is a different story.

Probably won't make a difference, and could make it worse.
The problem with PC power supplies for this purpose is that they have protection circuits and commonly the voltage droops significantly even with way less than the rated load, because there is an assumption in the design that there is a corresponding load on the 5V line, which with printers there isn't. How much the PSU droops under load depends a lot on the PSU, often cheaper ones are better in this regard.

You're better off with one of the EBay PSU's, even the 12V ones will put out 14 or 15V when you adjusts he trim pot, but you need to be comfortable dealing with wiring the 110V side of the PSU.

The reason SeeMe ship ATX powersupplies is they are cheap, and they are relatively safe to modify.
If you wire one of the ebay PSU's incorrectly, you can end up with the case live, and that would be a recipe for law suits.

I agree, and I've experienced that protection from a high end PSU.
Some time ago, I've bought a 650w Sentey and it shutted down every time the Hot end or the Bed started heating. I've tried balancing the load but never could.

Finally bought the cheapest 600w PSU in the market and worked ok. No noticeable changes comparing it with the stock one. Just a little bit, but it's not worth it.


For the leds you could add a very small PSU, the ones that are used for led strips.

Thanks for all the info guys. So how would increasing the wire gage of the heated bed help? I can see it would reduce the temp of the wires, but does this mean the bed will reach temperature faster?

My V2 has a 550W PS

Mine has a Corsair 750W modular PSU

Also using a 750W Corsair HX series PSU, it was in my main PC for about 3 years, had it for around 5, still going strong!

The trick is to find an ATX supply that will output higher amperage on the +12v rail. I think the stock supply does something like 16 amps. I put one on my machine that does 25A, and it's worked well.

EL Cuajinais wrote:Thanks for all the info guys. So how would increasing the wire gage of the heated bed help? I can see it would reduce the temp of the wires, but does this mean the bed will reach temperature faster?

All wires have a small amount of resistance. When you put current through resistance you get a voltage drop (and energy conversion to heat!). Larger gauge wires have lower resistance, which means a smaller voltage drop. So it's true that larger wires result in a slightly higher voltage delivered to the bed. But we're talking small numbers in this case, so you probably won't notice a performance increase solely from a wire upgrade.

The only way to dramatically increase performance is to increase the source voltage, which is what some people end up doing, often with a special supply just for the bed. Replacing one 12V supply with another 12V supply isn't going to change anything, unless the previous supply was failing to deliver 12V under load.

Well said.

However if you do find a good wire, thick enough to fill the entire connector, you will get better heat dissipation at the connector because there is more mass the suck the heat, a better connection so less resistance there.

While I was reading the forum, some people were having good success with 12V power supplies and the main difference was the wires going to the bed.

My V2 shipped with a 450W ATX PSU. It was a single rail unit rated at 18amps. If I just turned on the heated bed, it would take 22 minutes to heat it from 21C to 85C. Tonight I put in a 600W dual rail ATX PSU with the rails rated at 24amps and 20amps. My heated bed now takes 12 minutes to heat from 21C to 85C. I'd say if you get the right PSU it makes a considerable amount of difference.