# AMP draw Nema 23 stepper motor

Hi,

I have a NEMA 23 bipolar, 2 phase stepper motor, parallel wired and need to know how much current will the motor draw at the highest speed and torque.

I need as much speed as i can get. This is the data sheet of the motor: http://www.stappenmotor.nl/Schrittmotor%20data/Schrittmotor%2023%20F%20Serie.pdf

I have the one from the Datasheet with the F8 shaft Amps=1.25

According to the datasheet (last page) for parallel wired coils i need Quote: 2* current / coil. There are 4 coils in the motor and if the current per coil is 1.25 does this mean that i need a minimum of: (2*1.25)*4 = 10 Amps power supply??

Or is it just 2*1.25 =2.5 Amps power supply??

hope some can help. Can't find anything good on the web.

N

If the coils are wired in parallel there will be two coils each drawing 2.5 amps. But they will not both be drawing power at the same time so, on average there will be a current draw of about 2.5 amps.

You have not said exactly which motor you have. The coils have different resistances for the different motors. If we assume you have the motor with 0.9 ohm coils or a nominal 1.1v then with 2.5 amps it will need 2.5 * 1.1 = 2.75 watts - round it up to 3 and that will give you a better guide to the power supply you will need.

Note that the nominal voltage is largely irrelevant. Stepper motors work better with higher voltages. But make sure you have a specialised stepper driver that can limit the current to protect the motor. For a 2.5 amp motor I suggest a stepper driver that can handle at least 3 amps, and 4 would be better.

These links may help Stepper Motor Basics Simple Stepper Code

...R

Hi,

Thanks for the explanation. It helps a lot!

It is a nominal 1.1v motor.

I have a DRV8825 from polulu:https://www.pololu.com/product/2133

This one is rated 2.2A per coil. If i get it correct driver can handle 2.2A / coil. so i will be missing additional 0.3A?? But while running the motor with this setup driver does not get really hot? as ik would expected?

With driver of 4A would you recomend?

Thanks for the help.

P.S. i got 12Volt 4.2Amp power supply.

A DRV8825 won't be capable of driving that motor. It will overheat and shut itself down unpredictably. Don't try to use electronic components at the limit of their capacity.

Google stepper driver 4 amp should find you something suitable.

Your 12v power supply should be fine.

...R

Hi,

I found this driver for my 2.5 AMPS motor. https://reprapworld.nl/datasheets/SDTB6600.pdf
I think this should be better?

I have also another stepper motor (parallel wired) with 1.5 Amps per coil and nominal voltage of 2.1.
Specs:

With your calculation i come to 3.0*2.1 = 6.3 Watts?
Does this mean i need for the second motor a stepper driver of minimum 7amps?

I'm looking on the web for a driver with over 6 amps output. And gettings stuck because all of these drivers have an minimal input of 20Volt. And i use 12Volts. Can i switch over to 24 VOLTS power supply? Or is this not possible with my steppers?

Hope someone can explain this a little bit.

tnx a lot for the help

N

Kumalix: I found this driver for my 2.5 AMPS motor. https://reprapworld.nl/datasheets/SDTB6600.pdf I think this should be better?

What did I say earlier - why do you think I might change my mind?

With your calculation i come to 3.0*2.1 = 6.3 Watts? Does this mean i need for the second motor a stepper driver of minimum 7amps?

No. It is a 3 amp motor if you connect the coils in parallel.

You need to do some study about volts amps and watts - it is very basic knowledge for anyone working with electricity.

I don't have any suggestions to make about specific stepper drivers - I don't have any high current stepper motors. You will have to do our own research.

...R

Kumalix: Hi,

I have a NEMA 23 bipolar, 2 phase stepper motor, parallel wired and need to know how much current will the motor draw at the highest speed and torque.

It always draws the same current, since its a constant current motor (well, constant I-squared total for the two windings to be strictly accurate).

Its the motor driver that draws more current as the motor runs faster under load.

There are rules of thumb for sizing power supplies for stepper drivers, there is no easy calculation you can do unforntunately.