reprap

More power

I ordered two new power supplies for the 3D printer. The heated print bed is basically a big 1.2 ohm resistor. At 12 volts it draws 10 amps and so only puts out 120 watts, which isn't enough to get it up to the desired 110*C. The recommendation of the group is to run it at 24 volts at 15 amps or 360 watts; the guys that have switched to that power supply can hit 110 degrees in under 2 minutes.

I also went ahead and got a separate 12v/12a power supply of the same form factor so that I can just put them both in a box and not screw around with this hokey trying to use an ATX power supply for something it wasn't designed for.

While shopping for 24 volt power supplies it was apparent that there are a lot of people toying with CNC at home. And it's surprising how cheap really hefty power supplies are these days.

  • +1 by Megan Totusek
  • Todd Johnson - Is the underside of the print bed thermally insulated?
  • John Ridley - Well, pretty much. It's mounted at four corners to a piece of 10mm plywood by M3 screws and just an M3 washer between it and the plywood. It's not a good idea to mount it hard up against anything because it may warp the print bed slightly.
    One guy said that he throws some newspaper over it to help it get up to temp but that's a weak fix because it still can't hold the temperature once printing starts, especially since one of the best ways to improve output quality is to run a fan to cool the object as it's printing.
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