Linear bearings

Part: Linear bearings
Designers: Timothy Schmidt
Tools: 3D printers
Files: linear-bearing.stl


A linear-motion bearing or linear slide is a bearing designed to provide free motion in one direction. There are many different types of linear motion bearings.

Motorized linear slides such as machine slides, X-Y tables, roller tables and some dovetail slides are bearings moved by drive mechanisms. Not all linear slides are motorized, and non-motorized dovetail slides, ball bearing slides and roller slides provide low-friction linear movement for equipment powered by inertia or by hand. All linear slides provide linear motion based on bearings, whether they are ball bearings, dovetail bearings, linear roller bearings, magnetic or fluid bearings. X-Y tables, linear stages, machine slides and other advanced slides use linear motion bearings to provide movement along both X and Y multiple axis.


Static structures are not sufficient for reproducing most useful objects.

Bearings introduce backlash unless preloaded.


Bearings allow frames a variety of motion in relation to each other and other components.

Linear Bearings

To use the captive hex holes, insert bolts from the inside of the linear bearing, pointing out toward the frame.

To do

  • extend bearing block to encompass an additional frame in one dimension, bevel corner of that frame to avoid contact with the linear rail
  • modify corner reinforcement to allow for through-bolting with a double-length bolt instead of a triple.
  • hollow out bearing race portion of part, to allow for easier attachment of internal nuts and bolts.
  • design a version which bolts to standardized steel linear rail and linear recirculating ball bearing carriages


6mm steel balls

  • HGH15 / HGH20CA recirculating ball linear bearings
  • MGN12 recirculating ball linear bearings