As an extension of a series of models we have developed, a mechanical bent vocal-tract model with nasal cavity was proposed for educational and clinical applications, as well as for understanding human speech production. Although our recent studies have focused on flap and approximant sounds, this paper introduced a new model for the consonants [b], [m] and [w]. Because the articulatory gesture of approximants is slow compared to the more rapid movement of plosives, in our [b] and [m] model, the elastic force of a spring is applied to affect the movement of the lower lip block, as was done for flap sounds in our previous studies. The main difference between [b] and [m] is in the velopharyngeal port, which is closed for [b] and open for [m]. In this study, we concluded that 1) a slower manipulation of the lip block is needed for [w], while 2) [b] and [m] require a faster movement, and finally, 3) close-open coordination of the lip and velopharyngeal gestures is important for [m].