MakerBot Industries

Ah, thank you!

I knew this was a question for the forum :-)

Yeah to what jetguy said.

One other thing. Possibly better to put the EC on the first plug of the run so that it is not - split off - from the power supply. What I mean - Look at the plugs. They attach from one to another. Use the first in the chain. Not critical but, just a minor point that full power will come directly into the EC from the PSU through the first plug and then chain to the secondary load.

If you look at the picture again you see the first in the chain goes to the EC.
Even though this setup works it draws too much 12V power from a single yellow wire (and the power to the two steppers comes on top of that).
A better setup (thanks to Ed Nisley) is to put the EC on a separate wire. Normally a computer power supply has a connector with 2 yellow and 2 black wires. If you reuse these wires to supply power to the EC (two yellow wires going to the same pin, I know…) and then also reinforce the leads on the EC board with extra wire.
Glad to hear Makerbot has switched to a different PS as the original one was really wimpy.

So you mean getting a molex connector from somewhere and putting it on the end of an unused cable of the PSU?

Yep, that's what I mean. Alternatively you could just solder the wires to the pins on the EC board. There is also an alternative design where the wires are connected with additional pins directly on the mosfets.
Ed Nisley's blog at http://softsolder.com/ is a highly recommended read.

I wouldn't sweat it much on the new supplies as there are a number advantages over the old ones MBI was using. The wiring is much heavier on the new supplies and thus even the added load of 2 steppers (Z is less than 0.4 Amp, and X is only 0.86 amps) is not likely to cause an issue.

The big deal was using a splitter as that added more resistance. Also, try not to unplug-plug the one into the extruder more than once. Each time a molex is plugged in, it's resistance goes up, meaning it's more likely to fail.

Thank you both in anycase.

I just ran my first extrusion test and nothing went up in flames! :-)