Cyber-physical systems are gaining momentum in the domain of manufacturing. Cloud Manufacturing is also revolutionizing the manufacturing world. However, although there exist numerous physical manufacturing machines which are network-ready, very few of them are operated in a networked environment due to lack of scalability of existing cyber-physical systems. Combining the features offered by cloud manufacturing and cyber-physical systems, we develop a service-oriented architecture of scalable cyber-physical manufacturing cloud with MTConnect. A testbed of cyber-physical manufacturing cloud is being developed based on the above scalable architecture. In this system, manufacturing machines and their capabilities virtualized in a cyber-physical cloud. Manufacturing operations are represented as web services so that they are accessible across the Internet. Performance of the testbed of our cyber-physical manufacturing cloud with MTConnect is evaluated and test results show that our system achieves excellent service performance of manufacturing operations across Internet.