Stepper Motor - 125 (200 steps/rev, 300mm Wire)

These steppers are a great way to get things moving, especially when positioning and repeatability is a concern.

Note: This is a Unipolar stepper, meaning that if you are going to drive it with a bipolar stepper driver, you can ignore the yellow and white leads and drive it using the remaining four.

  • Step Angle (degrees) : 1.8
  • 4-Phase
  • Rated Voltage: 3V
  • Rated Current: 2A/Phase
  • 1/4" Diameter Drive Shaft
  • Holding Torque:
  • NEMA 23 form factor

Stepper Motor - 125 (200 steps/rev, 300mm Wire) Product Help and Resources

Core Skill: Robotics

This skill concerns mechanical and robotics knowledge. You may need to know how mechanical parts interact, how motors work, or how to use motor drivers and controllers.

4 Robotics

Skill Level: Experienced - Your experiences should include working with stepper motors and feedback system. You may need to understand how encoders and more complex control systems work.
See all skill levels

Core Skill: Electrical Prototyping

If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.

3 Electrical Prototyping

Skill Level: Competent - You will be required to reference a datasheet or schematic to know how to use a component. Your knowledge of a datasheet will only require basic features like power requirements, pinouts, or communications type. Also, you may need a power supply that?s greater than 12V or more than 1A worth of current.
See all skill levels


Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • Shannon2 / about 13 years ago / 3

    Consider replacing the photo showing the wire leads. I nearly didn't consider this stepper for purchase because it only appeared to have 5 leads. Only when I zoomed in did I notice the blue lead partially hidden behind the black one.

  • Grant4 / about 13 years ago / 3

    Would running this at 5 volts damage it? (Using the easy stepper)

    • Jagrolet / about 13 years ago / 3

      No. You probably want to run it at 3-4 times the rated voltage. Seems counter intuitive I know but thats common. To achieve high step rates, the motor supply is typically much higher than would be permissible without active current limiting. For instance, a typical stepper motor might have a maximum current rating of 1 A with a 5Ω coil resistance, which would indicate a maximum motor supply of 5 V. Using such a motor with 12 V would allow higher step rates, but the current must actively be limited to under 1 A to prevent damage to the motor.

      • Member #150261 / about 12 years ago / 2

        I am wondering how to limit the current - I am using this with the bigEasyDriver, supplying it 12 V. It is drawing up to 1.6 amps but you're saying limit the current to under 1A? Also, how do you know the 1 amp current limiting? I didnt see itin the datasheet

      • LineKernel / about 12 years ago / 1

        Waouw , THIS IS a great thing to know , i could not understant how to power this motor , or couldn t understand why no driver on Sparkfun was compatible with this motor

        I have learn something valuable here Thank you !

  • ben ventura / about 11 years ago / 2

    can anyone comment on the implications of driving this uni-polar stepper with a bi-polar driver (I'm looking at the BigEasy driver.) .. pros, cons, things to know, etc?

    • ben ventura / about 11 years ago / 3

      other than not using the yellow & white wires as mentioned above, that is..

  • Member #341875 / about 12 years ago / 2

    Is the holding torque adjusted as well as the motor turning torque by adjusting the current on the Big Easy Driver? For my application, holding torque is not critical, but turning torque is. Can I increase turning torque without increasing holding torque (it wastes battery power)?

  • Member #48177 / about 13 years ago / 2

    Anyone have any idea what the fastest RPM achievable is with this motor? Thanks.

  • Member #463722 / about 9 years ago / 1

    I bought this motor wanting to learn how to use one for a DIY CNC machine. I knew nothing about stepper motors and had no experience using a motor anywhere near this powerful, but I ordered an H-bridge (SN754410) with it and got started with the bipolar driver circuit provided on the data sheet. Bread boarding was a nightmare (requires the H-bridge, a logic inverter, and 8 diodes), but it was a great learning experience. I used a 6V DC wall adapter to power it and an Arduino UNO to generate the pulses. I later tested it with 9V and 12V supplies too. I strongly recommend buying the Easy Driver or something similar to control this, but if you're interested in learning how the circuitry works, tinkering with the H-bridge was a good experience.

  • lemuroid / about 10 years ago / 1

    This link has details on the motor lackng elsewhere. so, it may be of value to some of you....

  • lemuroid / about 10 years ago / 1

    I was struggling with this motor plus the adafruit motor shield v 1.1 (the old one). Finally got it working by figuring out the coil pairs (red goes with blue) and ( green goes with black) and then not connecting the yellow and white to ground.

  • lemuroid / about 10 years ago / 1

    This might seem like a silly question but what which wires form each coil pair or how would I figure that out. So far, I have white and yellow are ground but what about the rest?

  • Member #547355 / about 10 years ago / 1

    I have this stepper motor and the 68oz version. I was looking at potentially using this with them:

    However after more reading it says most 1.5V to 3V motors won't work with this shield. Has anyone tested this?

  • Member #391719 / about 10 years ago / 1

    Is this mount hole pattern compatible with any of your new robotics parts? If so is there a list available somewhere?

  • Member #230104 / about 10 years ago / 1

    Using this with Easy Driver and Arudino Mega. Just figured out that AccelStepper.h works (AND IS AWESOME) to control it. The only downside is the noise, especially when running at slow speeds (1/8 steps). Anybody have any ideas as to how to reduce sound other than shock mounts? Total enclosure not an option for my purpose.

    • that's just the nature of stepper motors, they are noisy, especially when driving them slowly. there's no real way around it. I don't think shock mounts would do very much.

  • Member #483420 / about 11 years ago / 1

    Does anybody know the micro steps and the millimeters per revolution on this?

  • Member #475258 / about 11 years ago / 1

    Can this motor be driven by an adafruit motor shield?

  • Member #474874 / about 11 years ago / 1

    So can this be run with the arduino stepper shield?

  • Member #469052 / about 11 years ago / 1

    Damn.. This thing is heavy.

  • Member #444407 / about 11 years ago / 1

    Any advice for a power supply for this motor? Preferably battery.

  • Member #446129 / about 11 years ago / 1

    How do I make this motor actually torque something? the shaft is perfectly smooth and I've already busted a couple motors by filing and dremelling the shaft down...these are so sensitive but there has to be a way to make the shaft able to torque something

    • MikeGrusin / about 11 years ago / 2

      Typically you'll attach it to something with a collar that contains a set-screw. McMaster-Carr is a good source of such components.

      • Member #492014 / about 10 years ago / 1

        I also wanted to drop a line and say that SDP-SI has a good assortment of 1/4" couplings/gears/pulley attachments (Stock Drive Products / Sterling Instrument; here is a link for pulley attachments that should work with this shaft:

  • Member #400306 / about 11 years ago / 1

    what kind of gear drive system are available to use with this motor, which type of system would provide less slop/back lash, and who sells gears and gear drive systems for this type of motor?

  • plasma leak / about 12 years ago / 1

    Can this motor be micro-stepped by big easy? Thanks in adavance JB

  • Member #372100 / about 12 years ago / 1

    Does anyone know the specific number sequence to output to the motor to move a half step (and also a full step)?

  • Member #370227 / about 12 years ago / 1

    Is seems a very strong motor (the torque). Does anyone know if I can use the motor driver "L6470 Stepper Driver Breakout " to drive this motor? Because the L6470 says a voltage of higher than 8 volts but here the rated voltage is 3. Can I use the built in overcurrent detection of L6470 to prevent damaging this motor? Thanks very much

  • Member #365871 / about 12 years ago / 1

    Since this is rated at 2A does that mean I can not drive it with a darlington array rated at 500mA max collector current?

  • Member #326474 / about 12 years ago / 1

    I get one coil to be 403 ohms, and the other 440ohms. Seems pretty out of balance- anyone else have a problem like this? I don't know enough to think if it's going to be a problem. I have tested it and had some problems, but I'm hoping those were more to do with my application and that they will be solved with I implement microstepping.

  • dgerton / about 12 years ago / 1

    Can someone explain the odd mount-hole spacing in the NEMA specification (47.14 mm or 1.856 in)?

  • Member #327012 / about 12 years ago / 1

    What power supply are people using to run these? I have 3 of these on my way and would like to know how to power them. Specifically, how many amps?

  • Levi5885 / about 12 years ago / 1

    Has anyone noticed that the picture they show doesnt match the data sheet? The picture shows it at roughly 63cm x 63cm and the data sheet says 56.4mm x 56.4mm max. Can someone ftom Sparkfun find out what the right size is?

  • proudgrover47 / about 12 years ago / 1

    Will this do with the EasyDriver? Also since its rated at 3V 2A, will it draw less current if I gave it 12V? Or would that be unsafe/unwise?

  • cpense00 / about 12 years ago / 1

    Will this work with the PhidgetStepper 4 unipolar controller? Thanks

    • I don't know the controller, but it should work. The motor is uni-polar, and so is the controller.

      • cpense00 / about 12 years ago / 1

        Thanks Robert! I wasn't sure if a 4-phase unipolar motor required something special on the controller.

  • Seshan / about 12 years ago / 1

    Would this be able to life a 2-3 lb object vertically?

    • cmagagna / about 12 years ago * / 1

      It looks like it. I just got 3 for a CNC mill I'm building and last night got the motor to lift itself + a Dremel using a 20 tpi threaded rod, a Big Easy driver, and a 24v power supply. Using the AccelStepper library i could get it up to about 2/3 in / sec before it stalled (around 750 rpm)

  • pgp / about 12 years ago / 1

    Can these withstand a 'bake' in a 100 degree C oven while NOT in use?

    That is, use the motor, disconnect the power supply, bake the motor, reconnect the power supply, and then reuse the motor?

    Thanks guys

  • Member #282917 / about 12 years ago / 1

    Hi, I bought this motor and i have an A4988 motor driver from pololu:

    This motor states 2A/Phase and the driver states 2A / coil. I assume this means the same but has anybody tested this motor with A4988 motor driver without burning the driver up. Just so that i know.


    • northbear / about 12 years ago / 1

      I would also be interested in hearing the answer to this question. Did you try it out? Did it work?


      • Member #282917 / about 12 years ago / 1

        Hi, I haven't been able to test this motor with the A4988 driver so much, even with load on the shaft. But yes, it works with the driver. What i have learned is that don't rewire the connections while power is on. Second thing is what i have assumed that i have learned is, that the main driver circuit shuts down quite easily. I plan to drive the motor with 1,5Kg-2Kg load and with the 400steps/rev. motor the chip shuts down with high torque/low speed settings. I bought a 14Lx14Wx20H (mm) heatsink and even that does not make the circuit do what it can... So you most definately need a big heat-sink and yes => DO OVERKILL the cooling part, put some fans and mega-huge heatsinks. I bought some heatsink paste from dealextreme and pasted a 5mm aluminum piece on the chip and the the machined heatsink on the aluminum piece. The paste was ok, but you should not put too much preassure with your finger on the heatsink before it drops off.

        Hope this clearifies a bit. Maybe some other driver chip tolerates larger currents.?

        If you don't need that precise movement. Consider a geared motor from for e.g. pololu. I bouth one and a driver for it and that driver wont get hot, at least what i have tested so far (with finger preassure load on the shaft)

  • DanFinlay / about 12 years ago / 1

    I heard you can make these go faster by turning off micro-stepping. What is meant by that?

    • LineKernel / about 12 years ago / 1

      here you have 1step = 1.9degre , with microstepping on , let s say 8x , you have 8 micro steps for 1.9deg , so your microcontroler send 8 pulses on you driver for your motor to make 1.9deg of rotation , if you are using 2x microstepping configuration , your microcontroler will then send only 2 pulse for your motor to make 1.9deg of rotation , and so on ,

      so no microstepping , your microcontroler will send one pulse and your motor will turn 1.9degre of rotation , so it is "faster" , but also has less resolution .

  • Member #295151 / about 12 years ago / 1


    I am new to the Sparkfun site and this is my first post. I ended up buying 2 of these motors for a project that requires the control of 2 linear actuators like a 2 axis CNC project.

    I realized that running the 2 motors hooked up exactly the same way resulted in one motor drawing nearly 3 times the amount of current than the other and vibrates much more. They perform the same operation (code) and with the same BigEasyDriver with the potentiometer in the same position. Does anyone know why they could be different?

    I almost suspect that the wires on one of the stepper motors are different than what the datasheet specifics. I am only using the black, green, red, and blue wires. The yellow and white wires are unused.

    Thank You, Andrew

    PS Great prices and service Sparkfun, from the University of Colorado Boulder

    • Member #295151 / about 12 years ago / 1

      Maybe it is not the wires, as I checked the coil/phase resistance and they are all within spec so not likely the wires, maybe I will just have to use different settings on the potentiometers of the driver boards.

  • dearmash / about 12 years ago / 1

    I'm new to the world of DC motors, I'm just curious, how would one attach a gear to this?

    The end result is a product that can open / shut an umbrella via a rotating hex nut. I figured a double gear in between, attaching it to the umbrella is easy enough, but I'm not sure about the gear attached to the motor.

    If I'm coming at this the wrong way, feel free to tell me that too.

    • LineKernel / about 12 years ago / 1

      but this product is not a DC motor ,(i thinkg) it is different , this one is a stepper motor , i think DC motor use a constant voltage , or a PWM for speed variation stepper motors are built with coils inside , and you shortly power one at the time to get a step rotation , that is why you need a driver. i am a bit new too , but that is what i understood . nice projet by the way !

    • DanFinlay / about 12 years ago / 1

      I found all my gearing needs met at McMaster-Carr. This motor uses a 1/4" drive shaft, and they have plenty of gears that will fit that out of the box. Some of your other gears might need to be machined at your local shop, but not if you're lucky.

      EDIT: Remember, if you get a "plain-bore" gear, it won't have a "set screw" which is required to hold on to any bar. You probably want one with a set screw pre-tapped, which you tighten with an allan wrench.

  • HungryMaggot / about 13 years ago / 1

    This is a 3 volts motor. EasyDriver supplies 7 to 30 volts, BigEasyDriver supplies 8 to 35 volts, SN754410 and L293D 4.5v to 36v, L298N 4.5v to 46v.-
    What can I use to drive this motor?? (please don't say 2 x 1,5 batteries)
    [I have lots of other (even bigger) beautifull stepper motors rated at weird low voltajes like this (2.63v, 5.2v, 2.93v, and so on) and high amps.. a trouble nightmare.-]

    • Ocean Controls / about 13 years ago / 1

      If you plug the motor directly into the rated voltage it will draw the rated current.
      Normally it is recommended to run them at 5-20 times the rated voltage and use a chopping stepper motor driver, like the easy and bigeasy drivers or a L297/L298 combo, to control the current.
      If you hook it up to an L298 at 4.5V but don't control the current you will draw more than the rated current and overheat the motor or L298.
      If steppers are run at higher than rated current or higher than about 20x rated voltage they can overheat and start to de-magnetise and lose torque.
      Also note that at rated current you can easily get a 60 or 80 deg (Kelvin) rise above ambient on motors like this, which is pretty normal.

  • GregA / about 13 years ago / 1

    Does anybody have any idea if this motor has enough torque to move something like this: Cereal Dispenser
    Looking to build an automatic cat feeder

    • Member #155921 / about 13 years ago / 1

      I just built an automatic cat feeder with this motor ( running at 24VDC, works like a charm.

      • GregA / about 13 years ago / 2

        nice! Do you have any photos? What did you use to dispense the cat food?

    • Yeah, it's pretty powerful. and of course you could gear it as well.

  • jimvela / about 13 years ago / 1

    These are really nice, but what would really put them over the top for me would be steppers with a rear shaft as well- that way we could add encoders, handwheels or similar.

  • Vegard / about 13 years ago / 1

    Could you please recalculate the estimated holding torque for the new stepper motors listed to give out the same data as the first one you had in stock for some time.
    the old one reads Holding Torque : 2.3kgcm
    Whats The kg
    cm on the new ones.

    • submission / about 13 years ago * / 1

      " edit " Ooops , I posted the same site as RobertC did . didn't see the link there at first . Good site by the way .

    • torque is measured a lot of different ways. use google to search for conversions. you can go between lb.ft,,, N.m, etc.
      here's a good site for that.

      • primeq / about 13 years ago / 1

        1m = 100cm and 1N = 0.102 kg (

        so 90 =

        90 x 1m/(100cm) x 0.102 kg/N The cm-units cancel, the N-units cancel, leaving .. . .

        = 90 / 100 x 0.102 = 0.0918 kg.m gives the answer as 91774.44 kg.m

        use numberfactory at your risk. Check this with any mechanical engineer you know; jeez - even check it with any other unit-conversion site.

        Small surprise NASA lost a mars explorer because they didn't know how to convert between units.

Customer Reviews

4.6 out of 5

Based on 5 ratings:

Currently viewing all customer reviews.

1 of 1 found this helpful:

As a first time user

I bought this motor for a DIY CNC machine with no experience with stepper motors or big DC motors. Overall, this is a solid motor. It's well-made and perfect for DIY projects. It's also pretty straight-forward learning how to operate it, although might require a little research if you don't know anything about stepper motors.

To work with a 3V supply is fun

By using a 3VDC supply, I could avoid a lot of energy waste if a (power) drop resistor is inserted to the higher voltage supply. A buck converter with proper current output is a must. Why did I use a 3V stepper motor like this one? It is just a change of taste. So far, as stepper drivers, there are Arduino Uno + L298; and 4017 counter + power transistors. No robots or CNC devs yet, but it's fun.

Excellent motor, and a good value

We used two of these in a project a couple years ago, and they were the best price we could find for this amount of torque. We used them in as bipolar motors (so we ignored two of the wires) and drove them with some A4988 stepper drivers from Pololu (same chip as Sparkfun's Big Easy Driver) with a 12V power supply to the driver. We were only able to reliably run them at about 1.4A per phase (because of the drivers) so we didn't get to push these motors all the way to the 2A that they're rated for. However, they worked just fine and had plenty of torque for our project.

Great Motor!

Bough this along with the EasyDriver and it worked just like it is supposed to. Plenty of torque for what I was trying to turn!

effective with room for improve applicability

Stepper motor works great if you understand the coding process. You will need loctite or some other industrial adhesive to attach it to most things. The cylindrical, smooth machined shaft is otherwise a challenge to work with.