Skip to content Skip to navigation menu

Optimising the performance of linear stepper motors

——The Electronic Specifier reports on MOONS' Industries (UK)

 

Recently launched in the UK, Motors and Drives specialists MOONS' Industries are delighted to offer their extensive range of motion control products, which includes three types of linear motion products.

These are Linear Stepper Motors, Linear Slides and Linear Actuators, all of which have been developed with features and specifications to ensure a stable and reliable performance, especially in high-accuracy engineering applications. When combined with a MOONS' closed loop controller, these linear actuators can be controlled via Fieldbus, timing and direction, or analogue / digital inputs, and when used in conjunction with an encoder, the driving force can also be controlled.

Optimising the performance of linear stepper motors

The introduction of linear motors can be traced back to around 1968, with a design undergoing significant streamlining over time, which today facilitates the successful integration of straight-line stepper motors into numerous high-precision linear motion applications without the need for external mechanical linkages.

Helping Engineers make the right choice when developing linear motion systems.

Engineers must prioritise determining a system's load, which can be categorised as static load or dynamic load. The motor size required is directly proportional to the overall load of the system. Dynamic load, however, is the pivotal factor that engineers must consider as it is subject to change due to motion, acceleration, and deceleration. It is crucial to account for the effects of movement and changing conditions. Therefore, engineers must consider both types of load to determine the appropriate motor size for their system.

Secondly, what is the linear running speed of the motor? A factor which is intricately linked to the lead of the screw, specifically, the nut, advances one lead when the screw lead is based on the desired speed of the system. Generally, for lower speeds, screws with smaller leads are recommended, whereas, for higher speeds, larger screws should be chosen to achieve optimal performance.

Thirdly, what is the system's accuracy requirement? Screw position: Linear precision, which refers to the discrepancy between the actual and theoretical stroke after the screw rotates the pitch circle, is the standard metric for assessing screw position.

Additionally, engineers should consider repeated positioning accuracy, a crucial factor determining the system's ability to reach exactly the same position multiple times. Also, 'backlash', the relative axial movement of the screw and nut when they are at rest, is also critical to overall performance. As systems operate over time, the backlash can increase due to wear and one way to compensate or correct this is to utilise a clearance nut. In applications where bi-directional positioning is required, even minor discrepancies in position can result in significant errors. Finally, does the installation of linear stepper motors conform to the mechanical design? How will you connect moving objects to nuts? What is the effective stroke of the screw? And what type of driver is matched?

MOONS' – Moving in Better Ways

Thanks to continuous development and independent research MOONS' are able to provide hybrid linear motion products, along with high quality spindles and nuts which deliver accurate and reliable performance, all of which address the key issues mentioned above. Their innovative LE Series of linear stepper motors are characterised by their external drive, where the lead screw is integrated with the motor rotor as the motor output shaft. The nut, which is external to the motor, is coupled to the drive mechanism, so as the motor rotates, the nut moves along the screw.

MOONS' – Linear stepper motor product series.

There are four types of linear stepper motors: external nut hybrid linear stepper motors, non-captive hybrid linear stepper motors, ball screw hybrid linear stepper motors, captive hybrid linear stepper motors.

  • External Nut Hybrid Linear Stepper Motors

    External Nut Hybrid Linear Stepper Motors

    External Nut linear actuator for easy installation and reliable performance. Available in NEMA 8, 11, 14, 17 and 23 different pedestal sizes, a wide range of lead and effective length screws are available. The nut has internal lubrication and zero maintenance.

  • Non-captive Hybrid Linear Stepper Motors

    Non-captive Hybrid Linear Stepper Motors

    Non-captive hybrid linear stepper motors for easy installation and reliable performance. Available in NEMA 8, 11, 14, 17 and 23 different pedestal sizes, a wide range of lead and effective length screws are available.

  • Captive Hybrid Linear Stepper Motors

    Captive Hybrid Linear Stepper Motors

    Captive linear actuator for easy installation and reliable performance. Available in NEMA 8, 11, 14, 17 and 23 different pedestal sizes, a wide range of lead and effective length screws are available.

  • Ball Screw Hybrid Linear Stepper Motors

    Ball Screw Hybrid Linear Stepper Motors

    Ball screw external nut linear stepper motors, the screw, and the motor rotor are integrated as the motor output shaft. The nut moves linearly along the screw as the motor rotates. Available in NEMA 8, 11, 14, 17, and 23 different pedestal sizes, a wide range of lead, and effective length screws are available.

 

Recommended articles:

 

How to Choose a Linear Stepper Motors?

Constant Force Technology for Linear Stepper Motors

Wiring Connections for Linear Stepper Motors

Ball screw linear stepping motor use precautions