As you may already know, it is incredibly important to choose an appropriate stepper motor for your equipment or application. The reason being is that if you choose a motor that is smaller than you require then you may experience a reduced maximum speed and torque or even missed pulses. However, on the other hand, if you choose a motor that is larger than you require, you may need to also purchase an expensive and powerful driver and power supply to be able to use it. So how do you choose an appropriate stepper motor and how do you ensure that it is suitable for what you need?

Choosing the Right Torque

Every stepper motor that is on the market will have a torque rating. This should be the first thing that you look at when choosing your motor. A stepper motor will also have a maximum current rating. This maximum current rating will also designate the torque number – as this is decided based on the assumption that the maximum current is flowing through the motor.

It can often be difficult to measure the amount of torque you require in a motor. In order to visualise this, imagine that you have a stepper motor with a 1 inch stick attached to the centre point of the shaft. When the motor is spinning, imagine you are able to stop the stick with your finger. The force that is used against your finger would be the torque.

Understanding the Maximum Current Rating

When choosing a stepper motor, you will also notice that they all have a maximum current rating on them. This is something you need to pay attention to before you buy the product. If you apply more current than the maximum stated on the motor then you are going to risk damaging it. If you run the motor at lower rates than its maximum rated current then you will not be using it to its full potential, it may be better to use a lower rated motor.

Understanding the Degree Rating

When choosing your motor it is also important that you pay attention to the degree rating. Almost all stepper motors are given a rating of 1.8°. This means that with every full step that a motor makes, there will be a 1.8° of difference. Therefore, if you step the motor, the motor shaft will rotate exactly once after 400 pulses. You may notice that if you decide to choose a cheaper or smaller stepper motor, then there will be far fewer steps in a full rotation. So how do you know which motor to buy?

Buying a Quality Stepper Motor

Thanks to the excellent resources that are now available on the Internet relating to stepper motors, you have a wide variety of choices when it comes to where to purchase one. Companies such as WEG Antriebe and their suppliers can provide excellent quality stepper motors as well as up-to-date and valuable advice on the best product to purchase; so do not hesitate to ask for advice before deciding on which stepper motor to use.

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