Linear rails vs Linear rods: Which are better?

Linear rods and linear rails ultimately perform the same function; they are parts of a linear motion system that move a load in a straight line from one point to another using an actuator. However, more subtle differences separate the two in terms of choosing one over and above the other for a specific application. Matara looks at linear rail actuators and linear rods and considers their relative benefits for different applications and purposes.

What is a linear rod actuator?

Linear rod actuators are the core components of many systems used in production, machine, and automation. They use pneumatic or electric power to move their load to the intended final position, extending the load beyond the body of the actuator.

What is a linear rail actuator?

A linear rail is an actuator in which the load is contained within the body of the actuator (the load’s travel length is within the rod’s dimensions), and therefore, the load travels along the linear rail. The linear rail itself is a rigid rail, usually manufactured from stainless steel, and containing ball bearings that create contact points between the carriage and the rail, which help to create a smooth motion along the linear rail.

What are the advantages of linear rails vs linear rods

Now that we know exactly what linear rods and linear rails are and the instances where they would be used in a linear motion system, let’s look at the advantages of each.

Linear rail actuators:

Space saving

A linear rail solution means that the whole assembly is no longer than the rail itself. If space is tight and you cannot afford additional equipment on top of the available length of travel, a linear rail actuator may be a better solution.

High rigidity

The linear rail has much less flex than a linear rod, thanks to its profile. This enables the linear rail actuator to move much heavier loads than a linear rod.

No load rotation

A linear rail is a more stable platform than a rod, meaning a load won’t rotate during movement, providing a more accurate and steady result. Linear rods can be doubled up to prevent rotation, but a linear rail offers a lighter, more straightforward solution.

High accuracy

Linear rails are generally manufactured to much tighter tolerances than linear rods, which means that they are less likely to flex during operation and that the carriage’s movement is smooth and consistent.

Made to measure

Because bespoke linear rails can be cut to the required length, the travel distance can be calculated and catered for to fit an exact requirement.

Linear rods:

Hygeine levels

Linear rod solutions are sealed units, and therefore, they are generally better for clean environments such as food and drink or pharmaceutical production. They can also be cleaned with high-pressure sterilisers.

Longer reach

If you need to push something further than the cylinder length or use it to integrate with other moveable parts or equipment, then a linear rod solution would be the better choice as there is not a permanent rail assembly in place.

Affordability

Linear rods are generally more affordable than a linear rail actuator solution. Making them a more cost-effective solution for our linear motion system.

Find linear rails and linear rod solutions at Matara

To answer the question of linear rails vs. linear rods, we conclude that linear rod and linear rail actuators, whilst at first glance, seem very similar because they perform the same function, are, in fact, suited to very different applications.

If you are looking at an electric linear actuator, then chances are a rod, or a linear rail solution would be a good fit. Which one is right for you will depend on your working environment and industry, the load specifications, the movement parameters, and the space available.

If you would like guidance in selecting the right solution, whether you want a bespoke linear rail actuator or a linear rod solution, contact us at Matara and talk to one of our experts, who will be happy to help. To learn more about linear motion systems, be sure to check out our case studies and technical articles.