Design of Spindle

The below Diagram illustrates schematic diagram of spindle. A spindle represents a shaft along with:

(1) Length 'a' that is acted upon by driving force F₂, and

(2) Cantilever of length 'm' acted upon by external force F₁.

The spindle is mainly designed for bending stiffness which needs that maximum deflection of spindle nose should not exceed a pre-specified value that is

Equation

d_max ≤ d_per

                                                               Figure: Principle of Working of Spindle

The total deflection of spindle nose contains deflection d₁ of the spindle axis due to bending forces F₁ and F₂ and deflection d₂ of the spindle axis because of compliance of the spindle supports. While the spindle has tapered hole in which a center or cutting tool is mounted, the total deflection of the center or cutting tool consists of deflections d₁, d₂ and d₃ of the center or cutting tool because of compliance of the tapered joint.