Crayfish (Astacus astacus) muscle stretch receptors show strong homology to mammalian muscle spindles and bipolar neurons in D. melanogaster. All are typical, non-ciliated, stretch-sensitive, afferent neurons. Such receptors are observed in many species and perform an important sensory role. However, they are poorly characterised. A previous study reported a bio-mechanical and behavioural model of A. astacus stretch receptors, which used the principles of elasticity and tension in a spring to describe the adaptation of a mechano-sensory ending. This model described the changing mechano-sensory currents in the receptor when subjected to a stretch protocol. This model was re-implemented and extended. Notably, additional descriptions of voltage-gated channels, that are suggested to contribute to stretch receptor mechano-transduction, were introduced. Our model now presents a more complete picture of the initiation of the mechano-receptor potential in response to a stretching stimulus. It describes the initial, stretch-mediated depolarisation; subsequent, voltage-activated channel activity and the transition from dynamic to static stretching. The inclusion of voltage-dependent sodium and potassium currents in addition to the initial mechano-sensitive sodium current allowed the model to account for most of the initial stretch response of the receptor. A further stretch-activated potassium channel is also suggested to be present. This preliminary model has potential for extension to describe fully the behaviour of non-ciliated mechano-sensors across species and predict the molecular mediators of mechano-transduction.