How To Calculate The Torque Of Your DC Electric Motor

There are a number of applications around the home and workplace that require the use of a DC electric motors. It operates by inducing a magnetic field through a series of wire windings that surround a magnetic rotor. When you need to replace your motor, it is recommended that you find out the torque of the old one (which is the name given to the force with which the shaft turns).

Step 1: Determine the power output of the motor. Generally, it will be in horsepower, but if you are using an American model it will be expressed in watts. Pull out the documentation that came with your model to determine the horsepower and revolutions per minute (RPM).

Step 2: If you cannot find the documents that came with your electric motors, you will need to calculate the horsepower yourself. You will need to divide the supply voltage by the engine’s resistance, which will give you its current. Then, multiply the voltage, current and efficiency (this will be a percentage that outlines the energy lost due to friction and heat) of the engine and divide by 746.

Step 3: Divide the horsepower by the speed of the motor (in RPM) and finish by multiplying the answer with a conversion factor of 5,252. This should provide you with the engine’s torque in foot-pounds.

Once you have established the torque of your particular DC electric motor, you will be in a much better position to find a brand new one that will meet the requirements of the application at hand. If you are unsure about some of the numbers and values asked for in the calculations outlined above, you can take your motor to a professional who will be able to do this for you.

Finding torque of servo motors

Servo motors have a great role in controlling the movement of robots, model airplane and helicopter. But what is it that makes servo motors works well? It’s the torque of the machines that makes is fit or unfit for the large machines like airplanes. People find the appropriate servo motors for their machines by calculating motor’s torque. Let us find how to do it.

• Place the motor on a flat surface preferably a table and secure it with shaft suspending at the table edge.

• Fasten the least weight object at an end of a thread and the motor shaft at the other end so that when motor runs the thread winds around the shaft. 

• Connect motor wire with the power point and observe the shaft and thread movement.

• If it winds around freely then stop the motor and replace the light weight object with a slightly heavier object and repeat the process to check if the motor still runs the same way.

• Keep increasing the weight until the motor stalls, then find the smallest weight the delayed or stop the motor. The smaller the weight you increase, the more accurate the calculation will be.

• Take measurement of the motor shaft radius and multiply the mass of the weight that stalled the motor by the radius of the shaft. The result you got is the torque of the servo motor.

If you know the way to calculate the torque, you can check whether the servo motors you bought is appropriate for your machine or not. So, the next time when you are not sure if the motor you purchased is appropriate or not, you can calculate toque with this simple method and get your answer.

Comparing Electric Motor Cars to Hybrid Vehicles

Have you ever considered what the differences might be between pure electric motor powered vehicles and hybrid energy cars? Several different models of hybrid vehicles exist, each with distinct advantages and disadvantages.

Parallel-Hybrid vehicles, for example, utilise both a traditional gasoline engine and another source of energy which provide power to the wheels in an alternating fashion. These combined power source vehicles present less of a pollution threat to the environment and make it easy for drivers to downgrade their reliance on fuel resources.

Series-Hybrid cars, on the other hand, use an electric motors to supply power directly to the wheels, while a gasoline engine is used as a generator for charging an on-board battery. In comparison to these hybrid models, pure battery vehicles have no combustion engine and rely on intermittent plug-ins to recharge the car.

This need for regular rest periods means that many people perceive hybrid vehicles as more convenient than pure electric motor cars. The convenience of an added gas engine comes at an extra cost, however, and for many users it is only needed in extreme circumstances.

Both hybrid and pure energy vehicles are widely considered to be cheaper to own and maintain than conventional gas powered cars. This is because the considerable cost of fuelling the vehicle with petrol is either reduced or cut out completely in both cases.

This cost factor is becoming increasingly important in our current environmental and financial climate, as the cost of powering conventional vehicles is becoming more and more difficult for average income families.

Why consider nameplate ratings while choosing electric motors

Electric motors when selected appropriately can serve you for years. Keeping its operation and maintenance part up-to-date can add up some more additional years to the motor’s life. However, there are certain factors that have to be considered while the selection of motor. One of them is nameplate rating. Most amateur people don’t actually realize the importance of nameplate rating and end up buying model that doesn’t fit into their requirements. 

As a matter of fact, electric motors are sized or rated under standard set of circumstances. In simple terms, there are different categories of motors which are designed for different purposes. While making choice, consider nameplate rating, as it determines the performance, service life, and describes procedures for curbing internal motor heat. 

If you choose electric motors having lower power than what it actually needs, it can create excessive load over the machine. For instance, if a motor with 40 HP (Horse Power) is over loaded under condition like accidentally using it to drive larger load than 40 HP or operating under low rated voltage, the machine will draw extreme amperage in order to supply the demanded power to manage the load. Overload power which when exceeds the nameplate rating the motor will turn hotter than its ability to bear temperature. This will in turn affect the machine in terms of deteriorated winding insulation and eventually shortens its life. This is due to the reason that the motor conductors and insulation are not designed to handle power loads more than the nameplate ratings. 

Nameplate ratings illustrate the operating parameters and convey the information to the users. It tells users that if the model is suitable for their application. Hence, it simplifies the process of selecting motors.

Brushless Electric Motors Frequently Asked Questions

Do you know next to nothing about brushless drives? Why not get started with your search for information by checking out some previous questions on the specifics of this type of machine? We have collected three of the most common questions people ask about brushless drives, including  popular misconceptions and prejudices to ensure that you make the best choices concerning your electric motors.

•   Can brushless drives be used in hybrid energy cars?

Yes! A high powered brushless drive coupled with a reliable controller can be used successfully in any type of vehicle, such as a car, motorcycle, golf cart, fork lift or boat. Many DIY kits are available for converting your vehicle into a more energy efficient machine and include parts such as the integral bridge, differential gear box and braking system.

•   How long does the average brushless electric motor last?

The longevity of any machine depends very much on the quality of construction and the application you are using it for. Other influential factors include the surrounding environment – including  such specifics such as air quality, humidity and floating debris – duty cycle, input power and load coupling. Generally, however, brushless machines last much longer than the brushed equivalents, as the product lifetime is limited only by ball bearing wear.

•   How is speed measured in brushless drives?

Determining the speed of your brushless machine can be a little confusing as there is no standard unit used in this field. The two most popular methods of measuring speed used by manufacturers, however, is by turns and using a KV value. As a general guide, you should understand that the fewer the turns on a brushless electric motor the faster the acceleration, whereas a higher KV number means faster acceleration.

How to choose size of the electric motors for your vehicle

For electric vehicle, lighter weight is what everyone recommends. Light weight means lesser load on the vehicle engine. Therefore while choosing electric motor you need to be watchful for its weight and avoid overcapacity motor. Over capacity electric motors don’t just increase the over all weight of the vehicle but also demands more batteries in storage bank. In this way, additional batteries further increase the vehicle weight.

Since electric vehicle conversion is about balancing, so it is you who will decide on the range and performance you expect from your vehicle. Performance of vehicle doesn’t simply need your wish your vehicle should also support your demand. Considering all the factors along with the selection of electric motor will help to achieve the conversion you are looking for. For this, you need to plan and calculate all the figures of your vehicle. Take engine capacity and size, vehicle size, maximum speed it can run on diesel, etc. in consideration. Getting right electric motor will prove to be rewarding.

If you feel trouble in finding right motor, then it is better to contact professional. Even if you pay some money to the professional to calculate and select right option, still it will be cheaper than the readymade electric vehicle. So don’t be fearful to spend on professionals, because it is better to take time and spend little more money than finally having a vehicle that doesn’t fit into your requirement and have retire earlier than its actual age. There are various vehicle conversion professionals who can suggest you the best option and get you the right motor.

Choosing electric motor for your car

Often while conversion of car it becomes a dilemma for people that whether they should choose AC or DC electric motor. Since, both of them have different features and challenges to face, it becomes a point of debate that which one is good for a car. But, comparing your requirements with their feature all perplexities can be eliminated.

As far as AC (Alternating current) electric motors are considered, they are, preferred by commercially produced electric or hybrid cars. This is because of their lighter weight than DC (direct current) electric motors and their ability to produce charge to the batteries when the car slows down. This process is known as regenerative braking. The AC electric motor is used to slow the vehicle down when the motor spins and generates current which is supplied to the battery pack.

The downside of AC motors says that there are also some challenges to be faced when they are installed. One of them is their excessive high cost. This is why often some people opt for DC motors when it is about reducing car conversion cost. However, this doesn’t mean that DC electric motors are can be graded low. There are many occasions when DC motors are suitable. If used ones are picked up from the market and reconditioned, it will cost quite low and also such choices last long because their servicing life is longer than conventional fueled engine. Reason, this electric motors have only one part that is moving, unlike diesel and gasoline that hundreds of moving part. Electric motors generate lesser heat, so almost no cooling is required and there no part frictions with each other so there is no need for lubrication either. So there are both pros and cons of AC and DC motors.