Where to Buy Linear Rails: A Guide to Sourcing High-Quality Options

Linear automation systems are designed to be efficient and cost-effective. Ensuring that linear rails and guides are specified and set up correctly is critical to facilitating the best output levels and reducing undesirable negatives such as friction, noise and reduced performance. 

At Matara, we’ve outlined some of the costly mistakes you can avoid to ensure that you know where to buy linear rails to best suit your linear automation set-up; next time you choose a linear rail for your application, avoid these common errors.

Lead Time and Costs

Linear rails are usually made from high-strength galvanised steel, stainless steel or aluminium. Aluminium has excellent corrosion resistance, is not magnetic and can be significantly lighter than the steel options; however, the cost can be substantially higher. If your application requires higher load capabilities, weight is not an issue, and lower corrosion resistance is not a concern, then galvanised steel would be more cost-effective. In terms of raw material costs, aluminium is between 2 and 3 times more expensive than steel; however, it is easier to shape and handle, with around just 33% of the density of steel. 

Once manufacturing, assembly and finishes are included, aluminium parts are around 30-50% costlier than similarly sized steel ones, although aluminium requires less work and no finishes due to its superior properties. Not only do the basic materials impact the cost and lead time of linear guides, but coatings and plating also add cost. This means that what might seem, at first glance, to be a cheaper material option may not be quite that straightforward once additional processes are considered, also adding substantial processing time to the manufacture of your linear rail.

Failure to test a full run

Once assembled, linear automation systems, such as linear guides, must be tested across the full travel run to ensure parallelism across the linear rails. From one end to the other, the push force should show consistency to within 20%; if there is an increase in force, it may be that the linear rails need realignment. Without the correct level of alignment for the linear guide, it may lead to friction, deflection and noisy operation, not to mention a potential safety issue.

Not specifying preload correctly

Preload is the elimination of internal clearance between the linear rail and carriage. This makes the system more rigid by creating a load on the linear guide, which reduces deflection when an external force is applied. Preload reduces noise, vibration, heat generation, and deflection when specified accurately. However, if the preload is not calculated correctly or the mounting surfaces are not of a high enough precision to match that of the linear guide, attempting to apply preload can lead to friction and reduce the overall performance of the linear automation system.

Failing to remember mounting features

The purpose of mounting features such as shoulders or alignment pins is to support the linear rails to ensure they perform to their specifications. Whilst linear rails are supplied straight, providing them with a stable support structure ensures they remain straight and parallel. Manufacturers specify mounting features to exact dimensions, and these should be included as part of the linear automation system design from the outset.

Not taking tolerance into account

The goal of linear rails is to guide motion in a way that produces the least amount of friction between the carriage and the rails. If the rails or the bearings/balls of the carriage are not within the correct physical specifications, then friction or failure can occur. 

Ultimately, this could result in heat, noise or damage to the parts. For linear rail specifications, tolerances must be accounted for in both the flatness of the mounting surface to which the rail is mounted and how parallel the linear rails are to one another; any friction seen during operation is likely due to rail misalignment or incorrectly specified mounting tolerances.

Find linear rail solutions here at Matara

If you would like guidance on where to buy linear rails to ensure that your linear rails are specified correctly and are of the right configuration for your intended linear automation output, be sure to contact us at Matara, and a member of our team will be happy to help.