One of woodworking history's greatest days was the union of the circular saw and guide rail, creating a track saw. The oldest photo evidence of it is this, an image taken in the early 1960s of Gottlieb Stoll, the founder of Festool (Wendlingen, Germany) (then Festo), demonstrating the company's first guide rail prototype with the AU 50 circular saw. What may get more attention, though, is how he's operating the combination—with a skinny extension arm. The arm featured a handle with an on/off button and, at least in theory, would help craftsmen make lengthy straight cuts. Although the combo guide rail and saw have received a number of upgrades through the years, becoming an essential item for custom wood floor pros, the precarious extension arm failed to convince customers and died on the vine.
