How To Choose the Right Brake Rotor?

What is a Brake Rotor?

Brake rotors are an important component in the braking system that stops your vehicle. It is a flat, circular metal disc that is mounted on the wheel hub. Vehicle’s brake pads clamp down onto the brake rotors, creating friction, which slows down the rotation of the wheel and ultimately brings the vehicle to a stop.

Goto ZCL to know more.

Over time, brake rotors can wear down due to the constant friction and heat generated during braking. If a rotor becomes too worn, it may develop grooves, cracks, or other defects that can compromise its effectiveness and safety. In such cases, it’s important to have the rotors inspected and, if necessary, replaced by a qualified mechanic.

Replacing the warped or damaged brake rotors is vital, not just for you, but also for the safety of the passenger and the world on the roads.

There are several different types of brake rotors available. If you are having trouble deciding which one to choose? We are here to help. You will be able to determine which are best suited for your car or truck, and how you can maintain them. 

1. How to choose the Right Brake Rotor?

2. What are different Types Of Brake Discs?

• Solid Disc Brakes
• Vented Disc Brakes

3. What material are Brake Rotors Made Of?

• Cast Iron Brake Rotors
• Steel Brake Rotors
• Layered Steel Brake Rotors
• Aluminum Brake Rotors
• High Carbon Brake Rotors
• Ceramic Brake Rotors

4. Which brake rotor is better, Smooth, Cross-drilled, Slotted or Drilled and Slotted?

• Blank or Smooth Brake Rotors
• Cross-Drilled Rotors
• Slotted Rotors
• Drilled and Slotted Rotors

5. How Do You Know It’s Time To Change The Worn-Out Disc Brake Rotors?

6. Can You Replace Solid Rotors with Vented Rotors?

7. Why Upgrade to New Rotors?

8. What Kind of Rotors Do I Need? 

9.What are essential Brake Rotors Buying Tips?

10. What is the Cost Of Brake Rotors?

11. The Best Brake Rotor Brands Which brake rotor to buy?

• Raybestos Brake Rotors
• Worldparts Brake Rotors
• Transit Warehouse Brake Rotors
• RS Parts Disc Brake Rotors

1. How to choose the Right Brake Rotor?

Selecting the right brake rotor is essential for ensuring the safety and performance of your vehicle’s braking system. Here are few simple things to keep in mind:- 

Make and Model of Vehicle – Ensure that the rotor you choose is compatible with your vehicle’s make and model, as different vehicles may have specific requirements 

Material – Brake rotors are typically made of cast iron, composite, or carbon ceramic. Cast iron rotors are the most commonly used for everyday driving. Composite and carbon ceramic rotors offer higher performance but are expensive. 

Rotor Design – There are various rotor designs, including standard, drilled, and slotted. 

    –  Standard rotors are solid discs and are suitable for regular driving conditions.

    –  Drilled rotors have holes drilled into them to dissipate heat more effectively, making them ideal for high – performance applications.

    –  Slotted rotors have slots carved into the surface, improving brake bite and aiding in heat dissipation.

Driving Conditions – For everyday commuting, standard rotors may suffice. High – performance options like drilled or slotted rotors might be more suitable for track events

Budget – High performance rotors which offer better performance come with a higher price tag. Consider the budget and balance it with your requirements.

Brake Pad Compatibility – Ensure that the brake rotor you choose is compatible with the type of brake pads you intend to use. 

Brand and Quality – Choose reputable brands which offer high quality brake components. As they have better quality control and materials.

Warranty – Brake rotor that comes with a warranty can provide you with assurance about the quality and durability of the product.

Reviews and Recommendations – Look for customer reviews and seek recommendations from trusted sources, such as mechanics, automotive enthusiasts or PartsAvatar blog. 

Always remember to consult your vehicle’s manual or seek advice from a qualified mechanic if you’re unsure about which brake rotor is best suited for your vehicle and driving needs.

2. What are different Types of Brake Discs?

The disc brake system relies heavily on the brake rotors, constituting half of its friction components. These rotors are typically circular metal surfaces crafted from cast iron and are positioned directly behind the rim with calipers facing either the front or rear. Brake discs can come in two variations: flat discs and vented discs. Let’s examine these types more closely.

Solid Disc Brakes

Vented Disc Brakes

3. What material are Brake Rotors Made Of?

Cast Iron Brake Rotors

Steel Brake Rotors

Layered Steel Brake Rotors

Layered Steel Brake Rotors involve laminating sheets of steel together, providing durability and resistance to warping. They are long-lasting in nature, requiring less frequent repairs or replacements.

Aluminum Brake Rotors

High Carbon Brake Rotors

Ceramic Brake Rotors

4. Which brake rotor is better, Smooth or Cross-drilled or Slotted or Drilled and Slotted?

Blank or Smooth Brake Rotors

Blank or smooth brake rotors, commonly found in factory-equipped vehicles, provide a seamless friction surface for brake pads to engage. This setup generates the necessary friction to slow down your vehicle. Opting for smooth rotors is a popular choice due to their affordability, cost-effective manufacturing, and reliable braking performance over extended use.

Pros: –

• Cost-effective option.
• Reduced likelihood of crack development due to absence of drill holes or slots.
• Suitable for vehicles not subjected to extreme or aggressive driving conditions.

Cons:-

• Slower heat dissipation, potentially leading to faster brake pad wear.

Cross-Drilled Rotors:- 

These rotors feature drilled holes for rapid heat dissipation, ensuring extended braking performance and minimizing brake fade during heavy use. Additionally, they aid in swift water dispersal in wet conditions, preserving initial braking efficiency. Ideal for all-weather performance upgrades, especially for car enthusiasts.

Pros:- 

• Effective in hilly areas, allowing for quick water drainage.
• Reduced water presence enhances brake performance.
• Assists in rotor cooling.

Cons:- 

• Aged rotors may exhibit worn drill patterns, impacting vehicle aesthetics.
• Not recommended for racing vehicles due to faster wear and potential cracking.
• Prone to earlier failure due to repeated heat and cool cycles.

Slotted Rotors:- 

These rotors feature thin slots or lines on the surface, akin to cross-drilled rotors. They enhance cooling and water dispersion. Unlike cross-drilled rotors, slotted ones prevent clogging from mud and debris, making them ideal for trucks and off-road vehicles. Additionally, they allow gases generated by excessive heat to escape, reducing brake fade.

Pros:- 

• Ensures consistent stopping power and reduces brake pad friction.
• Well-suited for heavy trucks, SUVs, off-road, and tow vehicles.
• Effectively removes glaze from overheated brake pads, improving braking.

Cons:- 

• Outer edges may crack if not machined properly.
• Shorter lifespan compared to other rotors, potentially affecting brake pad longevity.

Drilled and Slotted Rotors: – 

Combine advantages of both drilled and slotted types. Ideal for performance-oriented drivers seeking top-notch performance. Features include quick response in various conditions, rapid heat dissipation, reduced brake fade, and extended lifespan. They are a premium, albeit costly, option.

Pros:- 

• Excellent for wet climates with frequent rain.
• Ideal for carrying heavy loads.
• Exceptional for providing the necessary stopping power in heavy vehicles.

Cons:- 

• Not recommended for racing due to potential for cracking.
• Cannot be resurfaced; replacement is required if damaged.

5. How Do You Know It’s Time to Change the Worn-Out Disc Brake Rotors?

Here are the signs which tells us that it’s time to change worn-out disc brake rotors: – 

Squealing Noise While Braking – This indicates potential issues with brake pads, improper installation, or warped and damaged rotors. Worn-out rotors can accelerate brake pad wear.

Vibrations – Heavy vibrations during braking may signify rotor damage or warping, ranging from minor surface marks to significant grooves from prolonged contact with thinning rotors.

Longer Stopping Time – If brakes take longer to stop, it can pose safety risks. This could be due to brake line complications, damaged calipers, or leaky brake fluids. Consult a professional mechanic.

Warning Light – Some cars feature a dashboard warning light for brake maintenance. Note that these sensors usually have a similar lifespan to brake pads and should be replaced simultaneously.Car Pulling to One Side – A vehicle veering to one side while driving may indicate worn-out brake pads or sticking caliper guide pins or pistons.

6. Can You Replace Solid Rotors with Vented Rotors?

Yes, it is possible to replace solid rotors with vented rotors. But it is important to keep following points in keep in mind:

Compatibility – Ensure that the vented rotors you intend to use are compatible with your specific make and model of vehicle.

Caliper Compatibility – Check if the calipers on your vehicle are designed to work with vented rotors. Vented rotors are typically thicker, and they may require calipers with larger pistons.

Brake Pad Compatibility – Verify that the brake pads you plan to use are compatible with vented rotors. Some rotors may require specific types of brake pads for optimal performance.

Brake Bias – Switching to vented rotors may affect the brake bias of your vehicle. This could potentially impact the balance between front and rear braking. It’s important to ensure that the overall braking system remains balanced and effective.

Wheel Clearance – Vented rotors are thicker than solid rotors. Confirm that there is enough clearance within your wheel assembly to accommodate the larger size.

Professional Installation – It’s recommended to have a qualified mechanic perform the installation to ensure it’s done correctly and safely

7. Why Upgrade to New Rotors?

Upgrading brake rotors offers improved performance and increased vehicle safety. Benefits include: –

Enhanced Braking Performance – Worn-out brake rotors can lead to longer stopping distances. Upgrading to top-rated disc brakes reduces brake fade and shortens braking distance.

Smoother Braking – Disc brakes provide a more responsive and less spongy brake pedal feel, with reduced vibration during braking.

Improved Wet Weather Performance – Premium disc brake rotors like cross-drilled or drilled and slotted types enhance braking in wet conditions by allowing water to escape quickly.

Extended Lifespan – Upgrading both brake pads and rotors simultaneously improves braking performance and increases their overall lifespan, ensuring maximum mileage.

8. What Kind of Rotors Do I Need?

Choosing vented disc brakes is a better decision, as they offer benefits in terms of both weight and performance. Vented rotors are notably lighter than their solid counterparts, thanks to the presence of strategically placed vents. These vents also play a crucial role in dissipating heat, significantly reducing the risk of brake fade. Consequently, vented brake discs exhibit prolonged performance and superior airflow compared to solid ones. However, it’s worth noting that these advantages do come at a premium price point, whereas solid rotors, being more budget-friendly, remain a popular and practical choice.

9. What are essential Brake Rotors Buying Tips?

Trusted Name – The brakes are an important component of your vehicle. So do not seek a big bargain on any of the brake parts. 

Choose Carbon-Ceramic Composite – This material is usually costly and if you can afford them, then just go for it. If a component has a higher carbon content, then it has a longer lifespan and offers better braking performance.

Close Attention To Warranties – Pay close attention to warranties for disc brake rotors, as they are limited and specific. Replacements are available only if there are any defects. Only a few high-performance brake companies provide lifetime warranty where the parts will be costly. So you will have to decide and balance between price and warranty.

Good morning!

“This article is an adaptation and translation of the guide written by a friend of mine Javier Loureiro in Spanish which can be found at the wonderful StaticBoards blog: https://www.staticboards.es/blog/motores-paso-paso/

I am not a native English speaker, and I translated this article as a personal exercise to learn more about steppers motors, and it’s specific vocabulary.“

I have many ideas and I am really looking forward to convert this blog into the reference guide for the Spanish maker community.

Therefore, I’ve been thinking for a while which content is really a must to be here.

Due the RAMPS 1.4 SB topic, i normally receive lots of feedback related to drivers and stepper motors. “Which one do I buy? Have you read about this one? What about the DRV or the A, are they really compatible?, and so on…”

Following that feedback, I decided to put together a strong guide on drivers and I started writing about stepper motors.

Soon I realized that the post was completely out of control having more than words and growing. After a sanity check I opted to focus only over the stepper motors, and leave the drivers topic and the popular discussion about DRV vs A for a later article.

I am certain you are thinking… another massive article about “how the stepper motors work”

Me too!

That’s exactly the reason why i decided to give this article more of a practical view, trying to write something more useful.

I will give you a trick list and real advice, which will help you understand the best stepper motor to buy, figure out which motor that old printer has, or how to connect those motors when your wonderful manual is in Chinese.

Let’s start!

Quick search:

• Stepper motors, what are they and why do i need one.
• What is inside of a stepper motor.
• Stepper motors advantages.
• Position control
• Speed control
• Fixed position (check translation)
• Maximum torque at low speeds
• Common problems with stepper motors
• Low efficiency
• Slow movement
• Very low torque at high speeds
• Feedback
• Types of Stepper Motors to buy
• Unipolar Stepper motors
• Bipolar Stepper motors
• Main specifications
• Number of steps per revolution
• Angle per step
• Micro stepping
• Speed-reduction
• Holding torque
• Dimentions and Standard NEMA
• Heat
• Resistance
• Voltage
• Shaft
• Shaft types
• Simple guide to identify which stepper motor you’ve got.
• Connecting stepper motors
• Longer version
• If you own a multi-meter
• Final conclusions

Stepper motors, what are they and why do i need one.

Surely you already know what stepper motor is, you probably have heard about them hundreds of times and you probably already own one. And no doubt if you have built a 3D printer you own a few.

Anyway, i will start from the very beginning.

• Why do i want to use a stepper motor?

Those are the means that will allow you to have precision and control of movement.

That is the main reason that robots, precision machines or 3D printers use them. Stepper motors are present in most of the robotics projects.

With stepper motors you can obtain a precise control over the movement using an Arduino or a PC. You can also instruct the machine to move exactly a number of centimeters.

Lets understand how do they move so we can take advantage of their capabilities.

Vamos a ver cómo funcionan para que podamos aprovechar mejor sus ventajas.

What is inside of a stepper motor

Stepper motors are composed of two parts.

The first part is the Stator (very cool word which i love and i had to throw in here!).

The stator is where the stator coils are hosted, and it is the static part. It has notches on top which will be magnetized when the current flows over the coils.

The rotor is obviously the part that rotates, and it is formed by magnets which alternate between the north and south poles. There are as many magnets as notches at the stator.

The basic idea is that when the coils get magnetized, the magnets will be attracted by the notches.

Here are a few screen captures of a very detailed and well done video where the full inside process is perfectly explained.

When the coil is magnetized in the north pole direction, the south pole magnetized teeth of the stator will get attracted, therefore the motor will be fixed firmly in its position.

When the coil is magnetized to the south pole, the magnetized teeth oriented in the south of the stator will repel, therefore the motor will turn a step.

You can find a video here where this guy explains very well using the animation where the screen captures are from.

Advantages of the stepper motors

Lets enumerate the most important advantages which you will have to consider in your project if you are going to use stepper motors.

Position control

The stepper motors require a digital circuit to move. Usually an Arduino board, or a more advance controller. But there is no way of creating a simple circuit to control a stepper motor.

That is the reason why they are very well adapted to robotics. Our program sends exactly the amount of steps required, and we know exactly the angle the motor will turn.

Since our digital controller electronics possess the simultaneous control with precision of several motors, we can create any movement we can imagine, from circles, to draw a logotype. There are endless possibilities.

In theory with this, we will know at any point the position of our robot. Although we cannot be 100% certain.

We will not know if the robot is trapped on something, or if it did step into an obstacle. For that we require an external device to provide feedback about those events.

In a different scenario. If the robot is in a controlled environment, like a 3D printer, we can assume with confidence that everything will work correctly and trust our programming.

Speed control

Not everything is about the position. Our program can control also the transmitted pulses speed.

Therefore, we can accelerate or reduce our speed in a controller manner at any point. We can control the inertia and the breaking, to achieve slow and fluid movement.

If you would like to learn more about how to manage the acceleration in a professional manner, you should not skip “The ultimate guide to the GRBL firmware”

Fixed position

A very important characteristic of the stepper motor is that they can remain fixed in a position. If we apply current to the coils, the motor will stay on the current position without any advanced mechanical means.

For example, this will allow us to lift a door or a weight and have it fixed in middle air.

Maximum torque at low speed

The stepper motors behave opposite to the common electric motors. They are stronger when their movement starts from a resting position, than when they are up to full speed.

Due this fact, they are an excelent option for your project which requires low speed but lots of torque (like a metal milling machine, for example).

Which problems do the stepper motors have

Not everything can be an advantage, stepper motors also have quite a few important disadvantages, lets go through them.

Contact us to discuss your requirements of Rotor Motor. Our experienced sales team can help you identify the options that best suit your needs.

Additional resources:
Application of Synchronous

Very low efficiency

Electromagnets vs. Permanent Magnets: Which Motor Reigns Supreme?
Top Deals on High-Quality Asynchronous Motors for Sale

Yes, the stepper motors waste a lot of energy, compared to the traditional electric motors. Therefore, they consume more current than common motors.

They also consume their maximum when in rest, so they tend to reach high temperatures.

They are slow

To turn a full revolution, the motor has to step 200 steps, one step at a time. Therefore a common electric motor will always go faster. If you need speed, you have to invest in a servo motor (which are more expensive), or get your hands on a motor with an encoder.

What is an encoder?
An encoder is a device which allows you to know the real current position of a motor.

Low torque at high speeds

If on rest they are very strong, just the opposite happens at high speeds. They suffer the same problem as I do when I go for a run, I run out of steam really fast.

Feedback

They don’t provide feedback.

Unlike servo motors, the stepper motors do not know their position at any given time, and they cannot adjust themselves. Your only option is to build a system by yourself to measure and correct their position.

What types of stepper motors are available to buy ?

Not every stepper motor is the same, therefore, not every driver is the same, either is compatible. The key difference is in the coils that the motor has.

For that reason, you have to be really certain on they type of motor you have before buying a driver.

To the point, these are the two types of motors that you will encounter in the wild.

Unipolar motor

Internally they have two pairs of coils. Each pair is obviously composed by two coils. One magnetized to the north pole and the second one to the south pole.

Those are the easiest to program motors.

At the first moment, the driver will let current to go through the coil which magnetizes north pole, and then will turn on the south pole one.

This way, the driver will only need to turn on and off each coil. This is the most important feature of the unipolar motors. The driver doesn’t understand about north or south, it only turns on and off coils.

The unipolar motors are usually the cheapest and less powerful ones.

The unipolar motors are uber simple, just a transistor matrix, therefore the cheapest and simpler.

The disadvantage of being that simple is that they don’t manage power sent to the motor.

The most known driver for those types of motors is the ULN, which is really simple inside.

Why would i buy an unipolar motor?
If you are looking for something cheap in the few dollars range, and without too much torque requirements, that is the right motor for you.

Bipolar motor

A bipolar motor is simpler inside than an unipolar motor, since it only has two coils.

The complexity of those motors is on the driver. That’s because not only it has to let current pass through the coil, it also has to swap the current polarity.

Thus on the first stage, the current travels in one direction creating a magnetic field north/south, and on a second stage the current direction is inverted, creating a magnetic field south/north.

The name bipolar motor comes from the fact that the coils are designed to swap polarity during movement.

There are a vast amount of drivers for stepper motors. The most known in the 3D printing world and robotics are mainly based on the Allegro A chip, and the Texas Instruments DRV.

For bigger motors, which require more torque, more powerful drivers are used. The most known and expensive are the Gecko. Those drivers can be found inside CNC machines.

Why will I buy a bipolar motor?
Overall the bipolar motors are more powerful, and are used inside 3D printers, CNC, cutters, etc. Besides, since the drivers are more advanced, they manage better power and include more advance features, like microsteps and so on.

Main specifications

Let’s enumerate the general specs which you will find when looking into stepper motors to buy.

Number of steps per revolution

The stepper motors don’t have a continuous motion, therefore they cannot position themselves in every angle.

They work like the seconds in an analog watch, which they only have 60 unique positions.

As expected, the more steps the motor has, the better resolution we could achieve but with a reduced speed.

The common motors used inside machines and robotics use to have 200 steps per revolution. That is 360º/200 = 1.8º per step.

Angle per step

That is a different view over the number of turns per revolution. It is the equivalent way to give you number of steps or angle per step. 200 steps per turn is equivalent to 1.8º per step.

Micro stepping

This is a topic which generates lots of questions. Specially since the RAMPS boards contain jumpers to select the number of microsteps.

The idea behind this technique is based on not sending 100% of the power to the magnets, thereby the motor will not complete 100% of the step.

The microstepping designed drivers send energy using a sinusoidal wave.

Using this technique, in theory, we lose torque and power, but we gain resolution and fluidity.

Con esta técnica, en teoría perdemos torque y fuerza, pero ganamos resolución y fluidez.

And you can really see it. If you deactivate the microstepping (just remove the jumpers on the RAMPS), the movement becomes abrupt. Personally, every machine i put together i always set them to the maximum setting.

Gearbox

If the motor is connected to a gear and the gear to another gear we obtain a gearbox.

If the second gear is bigger, we will apply more torque while trading speed.

If the gear is smaller, we will go faster while trading torque.

It is very common to use gearboxes, and there are motors which have then integrated, saving us the installation problems.

Gearboxes are specified in ratios. And it is very common to see number of teeth per gear.

An example, 32:8 means that we will go from a 32 teeth gear to one of 8. For each 32 revolutions, the second gear will turn 8, therefore the relationship is 32/8 = 4 times.

The use of gearboxes depends on the machine and the torque and speed required.

Holding torque

I have to admit that i had to search Google for the term. I’ve been always seen it referred as simply torque.

In lame terms, it is the measurement of the torque that a motor can apply to hold a fixed weight.

To measure it, imagine you have a 1 meter long staff, and on its tip we set a 1 kg weight.

Now we have to lift that staff with one hand only. Many people will not be able to do it.

Now imagine that instead of 1 Kg, we have 2 Kg. It makes things worst!

What about having a 5 meters staff and 500 grams?. Although there is less weight , to lift half a kilo at 5 meters distance with only one had is quite difficult.

That is why, we measure the torque in Newtons per meter, since it depends on the weight and distance to the motor shaft.

3D printers usually require a lot of torque at the extruder in order to push filament, especially the ones trying to print with a 3mm diameter.

To give you an idea, the traditional extruder Wade (the most known extruder for Prusas) is able to produce a torque of 40 Newtons per cm.

However a laser engraver it almost doesn’t require torque, since it doesn’t have to push anything.

The stepper motors usually have less torque than DC motors. But instead, it is easier to hold them in place.

To keep a DC motor standstill, it is required to re-calculate the position in a constant feedback loop.

Size and NEMA standard

You will constantly be hearing about NEMA16, NEMA23…

NEMA is the acronym for National Electrical Manufacturers Association.

When it says national, it really means USA. It is quite a paradox that every NEMA you buy uses the ‘national’ standard, but they are Made in China.

The number will indicate the size of the motor. To be more precise it will specify the front face, where the screws are located. NEMA17 means it’s dimensions will be 1.7x1.7 inches.

It’s implied that usually the bigger the more torque will provide. Although it doesn’t have to be like that. It is totally feasible for a NEMA14 to over-match a NEMA17. It depends on the manufacturer and the specs of the motor design.

If the motor will be in a dynamic part of the machine, like the head or an extruder, then the size will really matter. The bigger the more weight, that will generate more momentum.

The NEMA14 are very light, but they are difficult to obtain with the necessary torque. The NEMA17 are the easiest to find and the most common ones for Arduino projects.

Which motor to buy?
Álvaro Rey, from MakerGal: If you are in doubt about which NEMA17 to choose, always buy the biggest. If you are afraid of not having enough torque get one of big 70oz.

Heat

Bear in mind that motors tend to get into quite a temperature. If they work at top of their specs, it is not uncommon for them to get to 80º degree Celsius. And if you happen to use PLA plastic for your machine…

You might end in big trouble!

As an example, let’s imagine we find a NEMA14 motor which works with the required torque, but we want to get it to its limits, it is going to overheat a lot. In that case, if we try to hold it in place using PLA parts, we have to take into account that fact or use a NEMA17 which will not reach as much temperature.

Resistance

One of the motor characteristics is the internal resistance. How this influence us?

On one side it is the heat released. Due having more resistance, the motor will heat more.

And on the other side, being a high resistance could lead to not getting enough current for the motor to turn (this is the most serious problem when using motors with higher voltage like 24v or 36v). Anyway, I’ve never encountered this problem before.

Voltage

This value also generates lots of confusion. It is very common for the motor to have a value like 3.6V, but we obviously have a 12V power supply. What can we do?

The motor is just a copper coil, the value of the voltage is a way of telling you amperage. Since the resistance is a constant, and by Ohms law with constant resistance amperes are proportional to voltage.

Alright, in simple motors, as the unipolar, where drivers only let current through, it is key to not let too much voltage in, otherwise the motor will overheat.

But for bidirectional motors, it is very common to use advanced drivers, which manage correctly power consumption and they have a maximum power limitation. The driver will measure how much current is passing through and will cut power when we cross the limit.

That’s why the voltage is not what is relevant to us in those cases, we will manage the power by calibrating the driver.

Motor Voltage and the power supply
It totally different the maximum motor voltage than the driver voltage.

Shaft

It is important to check the shaft diameter and the length.

Make sure you are going to use the gears correctly and to secure the setscrews firmly.

Also, make sure the gear will fit in the motor and the shaft to not be too long.

I am quite pedantic over it since it is not the first time I suffered that problem, or that i have to short the length of a shaft.

Shaft types

There are 3 types

1. Round shaft. The most common one.
2. Flatted section shaft. It is round but it has a flat section. Therefore we can use them with a setscrew easily.
3. Threaded shaft. Since it is also very common to attach a threaded shaft to the motor, there are motors which already come with a threaded shaft installed to be used with a nut. It is even possible to order them to specs.

A Simple guide to identify the stepper motor you have.

You’ve got your stepper motor from Ebay, the manual is in Chinese and you don’t have a clue if the motor is unipolar or bipolar.

Summarizing quickly.

If 8 wires, it will probably be unipolar, 4 per coil.

If 6 wires, probably unipolar, 3 for one coil and another 3 for the other. This means each coil has its own ground.

If 5 wires, probably also unipolar. 2 for one coil, 2 for the other and a common ground for both coils.

If 4 wires, probably a bipolar motor, 2 cables per coil.

I’ve also found this video which can help you differentiate the motor type you’ve got:

Wiring the stepper motors.

This will be a guide to connect the most common stepper motors for 3D printers. They usually mount NEMA17 with 4 wires.

Quick version.

If the motor comes with coloured wires, the typical colours are Red/Blue/Green/Black

Issues: It is not guaranteed to be like this! Who knows where the motors come from, how are they wired, etc. I’ve known many people who were not able to make them work and at the end, they realized the problem was in the wiring.

Longer version

The most common drivers which the 3D printers and home machines use are bipolar. The most known drivers for bipolar motors are pololus a and DRV.

The motor will have 4 wires. 2 per coil, therefore what we have to figure out is which ones are the coils.

Figure out the coils
If we are going to wire a stepper motor, we have to figure out which wires belong to which coil.

We can name them coil A and coil B, or coil 1 and coil 2.

Luckily, the drivers designers decided to use both systems (/ironic)

If you read the driver’s label, the DRV specifies A2 A1 B1 B2 and the A specifies 1B 1A 2A 2B.

Just read it several times, and make sure you understand it is exactly the same.

If you have a multimeter

Very simple. Test the resistance between two wires. If there is a bit of resistance (less than 150ohm), then you have found a coil!.

If the resistance is infinite (0L), it means that the cables do not touch and then they are from different coils.

If you don’t own a multimeter, you can use a more entertaining way of finding out using LEDs with legs.

Connect one wire to one leg and the other wire to another leg.

Then you rotate the shaft generating current.

If the LED turns on, then you have found the coil!

It is quite important to rotate the motor in one direction and also in the other one. The LED will only turn on in one direction (when you generate current from the anode to the cathode). If it doesn’t turn on in any direction, then those wires belong to different coils.

Conclusions

My God! If you are here is because you are really worried about which stepper motor you need for your project.

The stepper motors are a fundamental part of electronics. It is the main component of many projects and it is quite important to know them well.

I hope this article helped you to get into your own conclusions. Or at least to learn more about how they worn inside and understand better how can you use them.

That is why I invite you to share here the project you are creating. If you are thinking about a 3D printer or a laser cutting CNC machine, or a robotics project using Arduino.

Also, if you liked it, please share it in social media so other people has access to this information and can be useful to them.

Gracias!

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