What do I need a shaft coupling for?

Shaft couplings are mechanical elements that create a connection between two rigid components. They are used to transmit power directly (more precisely: to transmit torque and speed), but cannot convert power.
In industrial applications, shaft couplings are primarily used to connect input and output shafts. This usually involves transmitting power from a motor or gearbox to another machine.

Shaft couplings in 3D printing

Shaft couplings can also be found in your home 3D printer. Similar to industrial applications, the couplings, which are usually flexible, transfer the power of stepper motors to the drive shaft. As a result, the Z-axis of the 3D printer moves.

Flexible shaft couplings - all-rounders for 3D printers

Flexible shaft couplings compensate for angular, radial or axial misalignment between the shafts and the axes. In doing so, they reduce backlash. This dreaded backlash is also referred to in 3D printing as Z-wobble, i.e. the displacement of the Z-axis.