The structure design of a micro-precision CMM with Abbé Principle

Abstract

This paper presents the design considerations of a micro precision CMM. The structure of this CMM consists of the bridge, the Z-spindle and the XY stage. A novel bridge designed in a pagoda shape will be proposed and analyzed to prove its superior stiffness with force balanced condition. A high precision spindle design with counterweight and thermal error suppression are considered. The design of novel a coplanar XY-stage that observes the law of Abbé Principle is particularly proposed. Constructing these three structural modules the developed small CMM could meet the Abbé principle and provide high geometrical accuracy of the structure. Designed CMM has measurement lengths in X: 25 mm, Y: 25 mm and Z: 10 mm. Driven by the ultrasonic nanomotor and fed back by the hologram scale, each axis can achieve 1 nm resolution.