CNC power calculation confusion

the motors are 9 watts each I am assuming peak but most likely constantly running or continuous. S 4 x 9 =  36 watts just for the motors your logics will be less depending on the complexity.

An 800 watt power supply will deliver more than enough. are you running your milling tool from the psu too, or is it powered itself like ben's dewalt is from the wall outlet? if it is from the psu you will need to make sure the power supply

can handle the voltage and current. What I would do is add all of your wattage up then go 10 to 25 percent above if everything is from the same psu. For instance if your motors are 36 watts total and the spindle is 300w and the logics are 20w then my total is 356watts I would most likely choose a 400watt power supply to handle the start or surge current.

the 400watt should work, my concern is does the controller step down the voltage for the stepper?

trying to find the input voltage for the stepper controllers.

the stepper drivers can take up to 50 volts.

for now its just the motors and logic. So that'll be 60 watts total...I think I can forgo my 400w supply and stick with my 100w 12v wall wart.

Thanks.

just another quick question but would phone or cat5 cable be good for 9-10w at 3v 3a? I've got a lot of both waiting for something to do with them.

I would recommend heavier wire in case you ever upgrade the motors. the 24 should be able to take it but going to an 18 - 22 should give you some head room at 3 amps you will cause the wires to warm up also length plays an important role too. how long are your cables going to be?

If I am not mistaken that would be power transmission so I would step it down to 13 to 16 gauge to have headroom.

If you have some old pc power supplies you may be able to run those if they are long enough.

I've got an old pc power supply but I'll be using a 12v brick since it's a bit easier and I've used them before.  The motors themselves have about 21 gauge wire leads on them. I've going to go for,as you said, 13-16 depending on what I can find, or maybe double/triple/quadruple up some phone cable (I might have enough to do that). Wire lengths will be under 7m at the longest, probably 3m average.

paralleling the wire would not hurt it would decrease the voltage drop across it and enable higher current carrying capacity. so that should work for you.