Why run two spindles in parallel instead of one faster spindle?

One spindle can only turn one part at a time, and on a short-cycle part the loading time dwarfs the cutting time. The TT-500GD machines both sides of two parts at once and the gantry swaps a finished part in 2.5 seconds, so the machine cuts while it loads — doubling throughput on a single footprint.

The TT-500GD is the smallest of Takisawa's TT-series parallel twin-spindle lathes, with two 5-inch chucks facing forward in parallel, each with its own comb turret and a D-type gantry loader.

• 5-inch + 5-inch chucks, 50 mm turning diameter
• 5,000 rpm spindles, 7.5/3.7 kW each
• Gantry loader with 2.5-second part exchange
• FANUC 0i-TF control, comb-type tool slides

Against a high-speed single-spindle lathe, the parallel layout keeps two workpieces in the cut at once, which is what closes the gap between cycle time and takt time on a mass-production line.