There are several variations on this procedure. The Fairchild runs the belt inside, to a cast-iron flywheel below the table. There are arguments for and against each of these methods. The Components Corporation gets the motor farthest from the turntable and the pickup, thus minimizing the danger of noise from the motor. For the same reason, though, it is rather bulky and unattractive, and requires the most elaborate mounting.
Direct drive uses metal parts only and can thus be machined to the closest tolerances.
And when something goes wrong, the repair may be expensive. It is, however, the easiest to repair. A turntable does not become a record player until you add a tone arm, which must be separately purchased and mounted. Like the custom turntable, the separate tone arm solves a multitude of problems. You will recall that the cutting stylus rides across the record on a bar from circumference to spindle, following a true radial path always at right angles to the line of motion of the groove.