Abstract: A machine in which a log is transported through the machine center for chipping or sawing a slab from both sides of the log in a single pass and/or sawing a side board or flitch from one or both sides of the log in a single pass and/or sawing multiple boards by reciprocating the log through the center of the machine. This invention relates specifically to the center carriage feed system having a bottom carriage and a top carriage in which the bottom carriage supports the log continuously for its full length and the top carriage utilizes hold down bars or dogs that engage the top of the log. The bottom carriage includes a log supposing vertical member having a transverse member at its lower end provided with a wheel at each end to engage widely spaced parallel tracks. One of the wheels and tracks are of V-shaped configuration to stabilize and guide the vertical log supporting member to reduce lateral deflection. The other track and wheels are flat.