The machine automatically pivots itself into alignment with the orientation of a log being drawn into the machine, and/or pivots the log, and is vertically adjustable to conform to the inclination of a log in process. To cut off an end piece of the log, a shear blade first makes a partial stroke cutting less than entirely through the log. Then the shear blade frame moves away from the input end of the machine, pulling in another length of log. Then the first cut is completed and the shear blade and shear blade frame retract to starting positions for the next cut. This cycle is repeated in automatic operation. When splitting is desired, as for firewood, the shear blade is utilized as a ram to force each end piece of the log through a splitter at the output end of the machine.