Ironically, these couplings are often used when building custom 3D printers for those same reasons. With this method interfacing anything at all to a motor shaft becomes mostly a matter of ...

Flexible couplings couple or connect rotating members such as motors and drive shafts while allowing misalignment ... Roller or silent chain couplings have sprockets on each shaft coupled by a chain ...

Face-to-face length is the sum of the motor shaft length, the pump shaft length, and the coupling insert thickness. Pump mounting styles cover the bolt type as well as the bolt flange dimensions.