Self-aligning carriages

Posted by Emelie Neckman, 2024-10-16

Some linear guide carriages come with a self-aligning feature that automatically compensates for angular misalignment in your setup. Think of them like a spherical bearing—they adjust the ball race angle internally if the rail isn’t perfectly straight due to tolerances or bending.

For example, rails mounted on an aluminium profile might flex under load and cause rail curvature. With a self-aligning carriage, the ball race adjusts to the rail’s shape, minimizing internal stress and avoiding reductions in load capacity due to misalignment.

The self-aligning feature ensures that the balls enter the loaded zone smoothly and distribute the load evenly across the ball row—even when the angular error is up to 1/6 of a degree (which is quite a bit in the machinery world!).

These carriages typically require two per rail for proper stability—similar to how a train uses front and rear bogies to handle curves.

While these carriages may have slightly lower theoretical load ratings compared to standard ones, the benefit is predictability—you're not adding unwanted stress due to misalignments. In flexible structures, lifespan calculations actually become easier, and the carriages often last longer anyway.

Highly underrated tech.

Common names for these types of carriages include:

• Self-aligning carriages
• Pendulum carriages
• Super carriages

Check out this video on the topic featuring Carry Lindholm from Bosch Rexroth.