A powered surgical handpiece, said handpiece including: a motor having a drive spindle; a chuck having: a drive shaft that is attached to the drive spindle of the motor to be rotated by the drive spindle, the drive shaft having a first bore for receiving a shaft of a cutting accessory; a collet attached to the drive shaft, the collet including a base, at least one leg that extends from the base and a foot attached to the leg, wherein the collet is held to the drive shaft to both rotate with and move longitudinally relative to the drive shaft and the at least one foot is shaped to seat against the shaft of the cutting accessory; and a lock assembly (240, 246, 258, 268, 270, 274, 284) configured to selectively longitudinally translate the collet relative to the drive shaft between a run state in which the at least one foot is held against the shaft of the cutting accessory so that the cutting accessory rotates with the drive shaft and a load state in which the at least one foot is able to flex outwardly so the shaft of the cutting accessory can be inserted into or removed from the bore of the drive shaft; wherein: the chuck includes an alignment collar separate from the drive shaft and the collet that has a non-circular opening that leads into the drive shaft bore such that when the accessory shaft with a cross sectional shape that matches the shape of the opening is inserted in the opening, retention features on the accessory shaft are aligned for engagement with the at least one foot of the collet and wherein said alignment collar is attached to said collet so as to both rotate with and move longitudinally with the collet. a motor having a drive spindle; a chuck having: a drive shaft that is attached to the drive spindle of the motor to be rotated by the drive spindle, the drive shaft having a first bore for receiving a shaft of a cutting accessory; a collet attached to the drive shaft, the collet including a base, at least one leg that extends from the base and a foot attached to the leg, wherein the collet is held to the drive shaft to both rotate with and move longitudinally relative to the drive shaft and the at least one foot is shaped to seat against the shaft of the cutting accessory; and a lock assembly (240, 246, 258, 268, 270, 274, 284) configured to selectively longitudinally translate the collet relative to the drive shaft between a run state in which the at least one foot is held against the shaft of the cutting accessory so that the cutting accessory rotates with the drive shaft and a load state in which the at least one foot is able to flex outwardly so the shaft of the cutting accessory can be inserted into or removed from the bore of the drive shaft; wherein: the chuck includes an alignment collar separate from the drive shaft and the collet that has a non-circular opening that leads into the drive shaft bore such that when the accessory shaft with a cross sectional shape that matches the shape of the opening is inserted in the opening, retention features on the accessory shaft are aligned for engagement with the at least one foot of the collet and wherein said alignment collar is attached to said collet so as to both rotate with and move longitudinally with the collet.