Wattage of a Prusa/mendel printer?

Does anyone know the wattage of a printing Prusa/mendel printer with a single extruder?

Thanks

Bob

With or without a heated bed?

well take the motor amps, then the hot end amps so max on my rig is 5X0.85x12 for motors but the drivers probably arent efficient so say 1 amp each, id say hot end is around 15 ish watts so about 75w without heatbed and then add the bed say 200 watts total, but it will be less since the motors pulse on and off and the bed is not always on.

There is a little more to the story here. What you really need is the voltage and current requirements of a mendel and different components. Wattage ratings of pc power supplies are not as accurate as you would think. Also consider the voltage drop on the 12 v rails.

You will need about 500ma at 5v, 7.5-10amps for 12-20v for the steppers and drivers circuits as well as single extruder, and about 12-15amps 12v for the heated bed. This is of course for 1 extruder. Add about 4amps per extruder as a safe precaution. If you ever over current, the supply will turn off on you, if it is a good one as a safety measure for you and for the device.

If you are looking at pc supplies look at the voltages and current supplied for each rail and add about a 20% buffer for your amperage requirements.

Hope this helps, IMHO.