A Guide to Selecting Your Linear Rail Actuator

Linear rail actuators are used widely in industrial settings, from micro-manufacturing environments through to heavy industry and hygienic processing plants.  The advantages of linear rail actuators are broad, from enabling bulky or heavy loads to be carried across a distance, to providing extremely precise, controlled movements for applications that require great levels of accuracy. This means that linear rail actuators are great solutions for many challenging environments where linear motion is required, but it also means that there are a wide range of options on the market, and choosing the right solution can be daunting. We’ve summarised below just some of the things you may want to consider when purchasing a linear rail actuator.

1. What load do you need to carry?

This is probably the starting point for your decision-making process. You need to consider the radial and axial load capacity of the carriage in addition to the moment capacity. Orientation, size and position of the load are also key considerations; for example, with particularly heavy loads you may want to position the load beneath the block and rail assembly, or you may look at a multiple rail configuration.

2. What distance do you need your load to travel?

The answer to this question will dictate your stroke length; if you are considering a ball screw actuator, for example, they are usually limited to around 1m, although if you choose large diameter balls this can be increased to 3m lengths. 

3. How fast do you need your load to move?

Speed will affect your production rate and operational efficiency, so it is an important question for most applications. You will also need to consider how much control you require during acceleration and deceleration, which can vary between applications and solutions. Ball screw actuators generally move at up to 1.5m/s when the distance travelled is shorter than a metre, but will require additional supports in order to achieve this at greater stroke lengths, affecting your chosen configuration.

4. Which orientation do you need your load to travel in?

Most linear rail actuators are built with horizontal and inclined mounting positions in mind, so you may need to allow for some additional features if you are planning to install a vertically mounted actuator. Safety must also be considered in this instance, because whilst many motion systems have vertical load safety features already installed, a ball screw actuator would provide an extra level of safety since they are unable to free fall due to their design. 

5. How much of a priority is accuracy?

If repeatability and/or precision of movement is critical in your application then this will impact your chosen solution. Linear ball screws are accepted to be one of the most precise linear actuators on the market because they provide tighter tolerances on the movement within each stroke as well as providing extremely smooth travel as a result of the ball bearings.

6. What level of maintenance are you able/willing to provide?

Whilst some guide systems are available with a pre-lubricated feature, the majority need regular maintenance, and lubrication lies at the heart of the maintenance plan, particularly for linear ball screw actuators. Lubrication is the biggest reason for failure of linear motion systems and so it is important that you factor this in when planning your system configuration.

As you can see, there is a process that you need to go to when specifying your linear rail actuator, and getting it right will result in a more efficient, productive plant. We would recommend seeking advice if you are not certain about the right configuration for you, and experts like Matara UK are in the ideal position to guide you through that process.