Abstract: A tool changer for a milling machine comprising a tool store, twin claw tool changer and microprocessor controller. Tool hangers in the tool store are mounted to an orbiting chain. The chain is driven by a servomotor to advance a tool hanger to the ready (exchange) position through the shortest distance without each tool hanger coming to rest as it passes the ready position. The tool exchange takes place with no movement of the orbiting chain after the tool exchange is initiated since the tool holder removed from the spindle of the milling machine is placed into the very same hanger from which the tool holder placed in the spindle was taken. The microprocessor keeps track of which tool holders are in which hanger no matter how many exchanges.