Abstract: Disclosed is a machine for supporting a log in a veneer lathe so that the log does not deflect. The machine has two rolls which engage the log opposite the lathe knife and nose bar. The rolls are mounted on a roll carriage having a kinematic linkage which maintains both rolls in positions tangential to the log throughout a range of log diameters. The roll carriage is powered by a feed screw mechanism which mechanically synchronizes the rolls' positions with respect to the knife and knife carriage. A control system is provided to automatically lower and raise the roll carriage or to operate it manually when desired.