Mechanical and electromechanical components for rapidly constructing a user-definable apparatus may include components that are reconfigurable into other construction set components, and that have at least one demarcation defining adjacent segments thereof. The demarcations facilitate reconfiguration of the components to produce other construction set components. Openings to substantially prevent sharp edges from being formed during reconfiguration may be included in the components. An electromechanical drive assembly having an integrated speed control and operable to receive interchangeable, non-circular drive shafts may be provided. The electromechanical drive assembly may be configured to attach to and self-align relative to other construction set components. One or more of the components may be provided with openings through which the non-circular drive shafts may rotate. The drive shaft may be locked in relation to openings of components that allow the drive shaft to rotate via a lock plate. A bearing plate may also be included.