Can I Replace an Existing DC Motor with a Brushless DC (BLDC) Motor?

The simple answer to whether brushed DC motor replacement with brushless DC motors is possible is yes.

Many companies are increasingly replacing DC motors with brushless DC motors in a wide range of applications. The main reasons for this is that BLDC motors and controllers offer improved lifespan, improved power density and improved mechanical performance.

In other words, they deliver more power from a smaller package, last longer and go faster (if you want them to)! That said, there are a number of things that you need to be aware of when considering replacing a brushed DC motor with a brushless DC motor and controller.

Things to consider when swapping a DC motor with a brushless DC motor

The key to making the transition successful is knowing the performance characteristics and key specifications of the DC motor that you are wanting to replace and then being able to make a good match with a brushless DC motor and controller

Once you have this specification then it possible to began finding motors that have the right electrical characteristics. It is important to remember that this does not need to be an exhaustive list but a focus on torque and speed requirements as well as the physical dimensions of the shaft and motor body will usually suffice.

It is also important to have a clear specification of what you need to achieve within your product or application. It may sound obvious but a slightly different shaft diameter or length or motor stack length or size can have a major impact on a motor’s suitability for replacement. 

Always bear in mind you will also need to use a brushless motor controller or brushless ESC to drive the brushless motor so make sure you also have room for this within the space you need. There will therefore need to be some thought put into the question of where the controller will be mounted in the application. It is always best to mount this as close to the motor as possible in order to ensure the best possible performance but if this is not possible in your application then our team are happy to advise.

Choosing the right BLDC motor driver or controller for your application

As mentioned above, with brushless motors you will need a brushless motor controller (sometimes known as a brushless ESC or BLDC motor driver) such as the ZDBL5 brushless motor driver in order to drive the motor.

This is because applying direct power to a brushless motor will simply lock it in one position. In order to make the motor turn you therefore require a motor, a controller and a method for telling the controller what you want it to do.

If you have been using a very basic DC motor then it is likely that you will simply want to apply a voltage and current and get the motor to turn at the speed and torque that it did before.

If this is the case, we can help.

Our engineers can custom programme the ZDBL Series to very closely match the performance characteristics of a previously installed DC motor. It does take a little time to get it right but once it is set up we will simply assign a part number and you can order the same pre-programmed controller at your leisure.

In addition, if you were to need something a bit more customised to meet some unusual characteristics or help meet a difficult specification then we can design a custom controller for your particular application

If this is what you are looking for then we strongly recommend that you contact us via email or online chat with a datasheet or part number of the motor that you want to replace. We will then review the best options available and get back to you with a proposal. Of course, if you have any questions at all about doing this please do not hesitate to give us a call.

Finer control of the motor

However, if you are looking for something with finer control then using a brushless motor controller from the ZDBL Series will enable you  to control the speed of the motor in a number of ways.

For example, the speed can be controlled by using external hardware such as pots or by using a 0-5v analogue voltage input (onto the brushless motor controller) or by using a range of communications protocols delivered from a PLC or other form of central controller.


It is worth re-emphasising the importance of the physical size of the motor in making the change as we have worked with some clients who have found the perfect motor specification from a torque and speed point of view but who have missed the fact that the brushless motor they had chosen had a 5mm shaft when they needed a 4mm shaft to make a direct replacement.

1mm difference can take up a huge amount of time and money so please do check. Beyond this focus on the key performance criteria of torque and speed and how you would like to control the motor. Once you have these specifications in place it is possible to source a similar brushless motor and use a brushless motor controller to drive it.

If you have any questions at all about what is best you can always contact us and we will be more than happy to help.


Categories: Brushed DC Motor FAQs, Brushless Motor Controller FAQs
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