Abstract: An assembly for holding a cylindrical workpiece for grinding, including a support frame having at least one support arm extending to initially hold the workpiece and operable to disengage from the workpiece during grinding, a tailstock slidably mounted on the support frame and operable to engage the proximal end of the workpiece, and a collet assembly mounted on the support frame and configured to receive and engage the distal end of the workpiece. The collet assembly includes a housing having an open proximal end, an open distal end, and an internal channel with an inner diameter. The internal channel extends along the length of the housing from the open proximal end to the open distal end and is adapted to slidingly receive a spindle. The spindle has a proximal end portion and a distal end portion. The proximal end portion includes a holding portion and the distal end extends from the distal end of the housing and is engagable with a drive mechanism.