**Gloria Del Río-Cidoncha 1, José Ignacio Rojas-Sola 2,\* and Francisco Javier González-Cabanes <sup>3</sup>**


Received: 25 November 2019; Accepted: 9 January 2020; Published: 10 January 2020

**Abstract:** This article presents both the three-dimensional modelling of the isochronous pendulum clock and the simulation of its movement, as designed by the Dutch physicist, mathematician, and astronomer Christiaan Huygens, and published in 1673. This invention was chosen for this research not only due to the major technological advance that it represented as the first reliable meter of time, but also for its historical interest, since this timepiece embodied the theory of pendular movement enunciated by Huygens, which remains in force today. This 3D modelling is based on the information provided in the only plan of assembly found as an illustration in the book *Horologium Oscillatorium*, whereby each of its pieces has been sized and modelled, its final assembly has been carried out, and its operation has been correctly verified by means of CATIA V5 software. Likewise, the kinematic simulation of the pendulum has been carried out, following the approximation of the string by a simple chain of seven links as a composite pendulum. The results have demonstrated the exactitude of the clock.

**Keywords:** Huygens's pendulum clock; computer-aided design; virtual recreation; kinematic simulation; CATIA V5
