Abstract: An apparatus for drilling matching dowel holes in at least two companion workpieces includes a frame with a top surface and a drilling mechanism driven by a motor. The drilling mechanism is slidably attached to the top surface of the frame and movable along a first drilling axis substantially parallel to the top surface. A centering mechanism automatically centers the workpieces with respect to the first axis by movement along a second axis. A positioning mechanism is rigidly attached to the centering mechanism and positions the centering mechanism such that each of the workpieces is positioned in at least two dowel hole drilling positions along the first drilling axis. The positioning mechanism includes spaced-apart first and second stop members which define first and second dowel hole drilling positions. A stop engaging member is positioned movably between the first and second stop members and rigidly connects the positioning mechanism with the centering mechanism.