A powered surgical handpiece includes a chuck assembly with a chuck having apertures. The chuck assembly is surrounded by a collar having slots on an inner face. The apertures and slots receive balls. In use, the collar is moved axially toward the handpiece against a spring force so that the chuck is viewable. A base tab of a cutting accessory is inserted into the chuck. When the collar is released, detents of the base tab are radially aligned with at least two balls and apertures. When a biasing spring moves the collar outwardly, the respective balls move radially inwardly into the detents to fixedly lock the cutting accessory. The handpiece includes a single eccentric gear shaft that receives a rotary force at one end and moves about an orbital path at a second end. An oscillator receiver of an oscillator receives the barrel. Movement of the barrel about the orbital path results in oscillation of the oscillator about its axis. The oscillator is fixedly secured to the chuck and thus oscillates a cutting accessory mounted therein.
