reprap 3d printer power consumption???

ok so i recently build my own repap 3d printer without using heatbed(using pla)..

and i wanted to calculate the total power cunsumption of my 3d printer in minute or hour basis so how do i calculate it???

i'm using 12v nema17 1.8amps 5 pieces,
12v 40w heater with 12v dc fan and 100k thermistor
i'm using12v 20ams 240watt power supply
?????????????????/

since you dont know factors like power performance or just how much a stepper coil is on vs off, or the hotend on/off ratio its extremely difficult to calculate

Much easy to simply measure it with a power meter

ok so what type of power meter?????/any link???

Well, you have a few choices.

An Ammeter is probably the easiest. This measures current. Put that on your DC line powering the printer, multiply amperes by volts and you get watts.

Still, what you're actually using doesn't represent a peak usage. You'll need some data on your motors, and a little on the electronics for real worst case, ie: how much power do you need for your supply.

The biggest consumer of power in a 3D printer is the heated bed. Fortunately finding wattage for these is pretty simple, they seem to generally be in the range of 150-250W.

The next biggest consumer of power is the hot end. These are typically 30-40W.

After that, the motors. If you know what you have set up as driver current, that's a start, though the actual driver voltage will vary, so wattage is a little difficult to know without going through the data sheet for the motors. Also, it's not like the motors use full current all the time. They tend to average out at some percentage of current draw. Also, not all motors are driving all the time, but even a stopped motor will have power going through it (holding torque)

The electronics are probably the lowest power requirement, but still probably 10W or so, so they do neec to be figured in.

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MBot3D Printer
MakerBot clone Kit from Amazon
Added heated bed.

Leadscrew self-built printer (in progress)
Duet Wifi, Precision Piezo parts

thanks i will try with ammeter

Not easy to measure as the things which consume the most electrical power are heaters and they are constantly being switched on and off in "bang bang" mode or controlled by PWM.

I did a few tests with one of those plug type power meters. Just a cheap one so the results might not be all that accurate. Mine is a largish printer and I have a mixing hot end so use 5 extruders (sometimes all at once). To keep the Bowden tubes short, I have the extruders mounted on their own gantry, above the hot end. So it's a CoreXYUV and the moving mass in the Y direction is about 3Kg. The bed is 400mmx 400mm x 10mm thick aluminium tooling plate with 6mm glass on top but insulation under. It's heated with an 800W (I think) mains heater. I have cooling fans on all the motion steppers but not the extruder steppers. Anyway, here are some results.

Electronics only powered up - 0.106 Amps, 14.3 Watts
Electronics plus some LED lights - 0.181 Amps, 26 Watts
Start bed heater - 3.43 Amps, 841 Watts
Consumption from power up to bed reaching 60 deg C - 0.088 Kwhr - @£0.20/Kwhr = £0.02
Watts to maintain bed at 60 deg C - variable between 40 and 246
Consumption and cost for a 17 hr print 3.361 Kwhr @£0.20/Kwhr = £0.67

So roughly 4p an hour when printing which I'm not too concerned about. That's with a pretty big printer and massively heavy print head by most peoples standards.

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I have a cheap Kill A Watt P3 P4400 meter bought off of amazon on one of my printers and it bounces around between 90-150 watts while printing. if I set the bed and hotend (50w cartridge) to a high temp (so both are 100% duty cycle) while printing it shoots up to around 600 watts. This particular printer runs the X and Y motors on a separate power supply set at 38v. Z, E, hotend, control board, lights and LCD on another 12v power supply and the heated bed is a 500w silicone running on 110v AC

Edited 1 time(s). Last edit at 09/03/2018 09:44PM by Bill Clark.