http://home.comcast.net/~tomhorsley/har … -udev.html

If you're referring to the orange thingy, that is not a switch, it's a locking tab that lock the PSU into the server backplane, and is not used in our setups.  These power supplies don't usually have a physical power switch.  They are ATX power supplies and they're powered on by the main server power switch. 

This is why you'll need the PSU pinout.  The back of the PSU looks like this:

ON the left you have a bunch of control & signal pins. The 6 large connectors are the +12V and 12V return (3 + 3).

Once you know the pinout, you'll be looking for 2 pins, one called PS_ON, the other PS_Kill.  Grounding these 2 pins will power non the PSU.  So you'll have to first connect PS_ON & PS_Kill together, then run a wire to a switch.  Run another wire from the PSU ground to the other connector on the switch.  That should be your ON/OFF power switch.

Then you'll need to connect the PSU 12V output to your Solidoodle.  Yous should first bridge the +12V connectors together then run a heavy duty wire from there to your Solidoodle power input.  Do the same for the 12V return.

That's it.  If you really want to get fancy, then you might want to buy a lighted switch, in which case, you should run 12V to the power switch LED as well.

Best thing to do is get a server PSU, and and wire it to your SD3.  One advantage of those server PSU's is that they are long and skinny, and can be mounted to the back of the SD3.  Then there's the 60A or so they can deliver on the 12V rail.  Unlike the average desktop PSU which may only have 15-20A available these beasts are true workhorses.

Add a power switch and you're set.  You can throw just about any mod you can think of into your printer and still not even come close to tapping all the power of the PSU.

Is this a good one?? I'm new to this. Looking to get something someone already has had luck with in case I have some questions about it.

http://www.amazon.com/Dell-Redundant-Ho … wer+supply

Also, is that not a switch next to the plug? If not how would I go about adding one? Thanks for your help everyone!

i want to print something to mount it to the back like pirvan.. friggin solidworks...

Or you could use some VHB tape to mount the PSU to the back of the printer.  That stuff is pretty much permanent, and some of these tapes are rated at 75-100lbs/in² holding strength.  The only way to take off is to use a thin blade to cut through it, then scrape it or rub it off.

http://www.amazon.com/3M-Scotch-4905-Ta … m_indust_2

P.S.  I know this isn't the place, but If anyone is interested in server PSU's, send me a PM, I have some I can let go for $50 shipped

Oh, and it would make any difference in my case, as I'm not using and enclosure on my SD3.

I wonder if you could port the exhaust from the cooling fan from that beast into the build chamber to heat it (hopefully no implied Patent Infringement)!

Add a power switch and you're set.  You can throw just about any mod you can think of into your printer and still not even come close to tapping all the power of the PSU.

Personally my favorite thing is to convert server powersupplies, or use a good genuine meanwell.  If you can, splurge for a higher watt one, but you shouldn't need to spend more than $50. Splurging for a higher watt one will serve you in that it runs cooler at a lower power and can give you room to get a more powerful heated bed.