This device uses a small electric motor to directly drive a plain steel shaft, which is supported by a bearing. The bearing is freely mounted on the shaft and sealed at the motor end. The control unit precisely manages the motor speed, which can be operated in either direction. The bearing includes four pressure taps along its axis and twelve pressure taps evenly spaced around its circumference. All sixteen taps are connected to a manometer through thin, flexible plastic tubes, allowing the user to observe the pressure heads at all points simultaneously. The bearing can be loaded by placing weight on an arm supported beneath it.