CoreXY Build: CoreXY Mechanism

CoreXY Explained

The corexy parallel kinematics mean's that the motors are the largest source of inertia within the system, and are stationary. This means rapid acceleration because the two stepper motors provide a means of moving both axes independently or simultaneously. The major benefit of the design is that the motors remain in a static position.

The corexy kinematics is a complex motion system where X or Y motors move together or opposite of each other to move the carriage from left to right or towards or away . If you were to move just one motor you would see the print head move diagonal.. If the two motors move opposite of each other the print head will move along the X-axis, If the two motors move in the same direction the carriage will move along the Y-axis.

CoreXY Kinematics

Two Motors

Both Motors Move Clockwise >> Carriage Moves Left
Both Motors Move Counter Clockwise>> Carriage Moves Right
Both Motors Move Opposite of Each Other>> Carriage Moves Toward & Away
One Motor Moves>> Carriage Moves Diagonal

Belt Path

A printer’s motors can be offset at different heights so that the belt routing runs a straight belt path and doesn't have to be twisted. But this belt routing path would also mean that on one side of the gantry the belt would have the teeth on the side of the idler wheel which wouldn’t run as smooth and could lead to artifacts within printed parts.

Mechanical Arrangement

The crossed belts configuration found on the SolidCore CoreXY y-axis must be completely perpendicular to each other to prevent any mechanical binding.

Linear Rail: Supported vs Unsupported

A crossbar made from u-shaped aluminum extrusion is used as a support for the linear rails. Depending on the rail length if the y-axis has an unsupported linear rail it could possibly lead to deflection. The load of the belt paths have to be balanced along the running plane with the pulleys. An unbalanced load can lead to the belts trying to slip off the pulleys and premature wear of the bearings.