Micro Servo Motor

Variable Load Speed Range – Being able to control the speed of the motor means there are many more applications for which a BLDC is suitable.

Continuous Torque Range – Electronically controlled motors like the BLDC are able to produce different torque and power outputs making them more versatile. ( micro servo motors can also provide high output torque and power. But there is more control with the micro servo motors when connected through a controller.)

Long Lifespan – A micro servo motor requires direct contact between the brushes and the commutator whereas micro servo motors have fewer contact parts, for example there is no friction between the brushes and commutator, therefore require less maintenance through wear and tear. This means they have a longer life span than the average DC micro servo motor.

Safer – Brushed motors have a tendency to spark due to friction with the brushes which can be a health and safety hazard in some situations. This is not a concern when using a BLDC.

Efficient – Brushes in a micro servo motor can reduce the efficiency of the motor whereas micro servo motors work on 85-90% efficiency which can end up being a cost-effective option for your business.

Compact size – Brushless motors are able to fit a lot of power, torque and speed into a small size envelope which can be advantageous as many modern precision products not only need to be powerful and reliable, but they need to fit into a very small space.

Quiet Operation – The lack of means brushes that micro servo motors are somewhat quieter than their brushed counterparts and produce less electrical noise and interference making them more suited to some industries such as medical, the food industry or other noise-sensitive industries.

Cost Effective – Although the outlay of a micro servo motor can be more expensive than a brushed alternative, over the lifespan of the motor there will be cost savings in reduced maintenance fees and machinery downtime.

Fully Customizable – Depending on the application the BLDC is fully customizable in regard to torque and speed as well as the size envelope. The motors can be run with sensors and without sensors. Brushless motors can also have more poles than a micro servo motor allowing for more precise control. Permanent magnet motors (brushed) are limited to the amount of poles they can have through the amount of brushes that can be fitted. Alternatively, there are a number of off-the-shelf options which suit a wide range of standard specifications.

Load
One of the most important and obvious requirements for a micro servo motor is determining the load. The main loads of interest for a micro servo motor are what the motor shaft will be rotating in any capacity. Any parts connected to the motor shaft will apply a load inertia. Specifically, the inertia of the load needs to be less than that of the inertia generated by the motor for the motor to function as intended. The moment of inertia for the motor is typically found on the datasheet. Oftentimes, designers will use a safety factor to make sure that the motor will still be capable of efficiently turning and handling a load that might not be exactly what was expected.

Electronic Control Functions
Another requirement for the micro servo motor that needs to be defined are the intended electronic control functions of the motor. In other words, before a micro servo motor is selected, the designer must know what kind of motion sequence or function the motor needs to be capable of before making a selection. The programmability and functions available with the included drive need to be considered.

Speed and Torque
Once the motion sequence has been established for the motor, the next step is to determine how fast the motor is required to turn and how much torque the motor needs to provide. Both of these characteristics will be a result of knowing the load in addition to how the load will be moved. Between similarly sized micro servo motors, it can be expected that a motor that provides higher speed will not produce as much torque as a motor that is only capable of a lower speed. It is important that when making a micro servo motor selection to not pick a motor that will be constantly running at its maximum speed. Continuous maximum output from the micro servo motor will decrease its lifespan and increase its maintenance time.

Power Requirement
Once the relative speed and torque requirements have been defined, the designer needs to select a power source that will be capable of powering the motor. This is not so much a step in the selection of the micro servo motor itself, but is something to consider if there is a limit to how much power can be supplied to a possible motor. A voltage requirement will determine the maximum power delivered by a motor in general.

Environmental and Installation Conditions
The environment that the micro servo motor is being installed in should play a large role in determining what micro servo motor to select. As a result of fast-moving and rotating parts, heat will be generated by the micro servo motor and transferred to the surrounding area, heating up the motor as well. The amount of heat produced by the motor also affects its performance, which is also typically denoted on the datasheet.

The physical size of the motor and what the motor is being installed onto also play an important role when considering the environment and installation conditions of a micro servo motor. While it might be easy to go with a large motor that fits within budget to oversatisfy torque requirements, the motor might not end up fitting in the preferred orientation if the designer is not careful.

Quality
The last, but not the least, important factor when selecting a micro servo motor is the quality. Depending on the allowed budget for the purchase, factors such as efficiency, accuracy, and reliability of the motor can and should be considered if the motor is intended for long-term use. If the motor is going to be used in a highly specific and calibrated application, then a cheap micro servo motor with poor motion control will probably not meet the requirements of the application over time.

Servo Cleaning Tips – micro servo motor Cleaning Steps
Start by opening up the micro servo motor. Gently bend the tabs holding the case together just enough to get them past the tabs. You’ll need to be patient and careful, but this shouldn’t be too difficult. This will expose the parts of the micro servo motor, which include the copper contact, the small gears, the large gear with the potentiometer and, of course, the motor.
The potentiometer is a disc with conductive charcoal stripes around it. You will see that the potentiometer is coated with grease. You want to clean off the grease that has been touching the copper contact. You will be able to identify this part from the grooves in the grease where the contact has touched it.
Using a paper towel, simply wipe off any contaminated grease, while leaving the clean grease intact, since the motor needs this grease to function.
Then wipe any dirty grease off the copper contact. Be careful not to press too hard — you do not want to damage the copper contact.
Once you have cleaned off all the dirty grease, transfer some of the clean grease onto the part of the disk you wiped off. This completes the cleaning procedure.

After Cleaning the micro servo motor
The only remaining step is to close up the motor. Be sure to position the gear with the potentiometer so that the arm attached is pointing away from the electrical connector on the other side of the case.
Hold the arm in place and gently push the halves back together until the case snaps back into place.
Put the micro servo motor back into operation and see if it functions normally. If it does, fantastic!
If not, unfortunately, your micro servo motor probably needs a more extensive repair. There are many reasons why a micro servo motor can go wrong, and a need for cleaning is just one. During regular use, parts of the micro servo motor can become worn out or even break, requiring replacement.