Johnford SL-60-2S

The Johnford SL-60-2S gives the 10 in twin-spindle lathe a longer bed: 900 mm (35.4 in) of Z travel between the main chuck and the 8 in sub-spindle.

Length changes what the second spindle is used for. On a short twin-spindle machine it takes over a parted-off piece. Here it can also grip the free end of a shaft while the main spindle drives it, so a part most of a metre long is held at both ends, turned along its length, and then finished at each end in turn. Splined shafts, pump shafts with features at both ends and long sleeves are typical. Both chucks need to run synchronised for that, which is a control function to confirm in the quotation.

The main spindle is the 15 / 18.5 kW (20.1 / 24.8 hp), 3,500 rpm unit with an A2-8 nose and Ø76.5 mm (Ø3.1 in) bar capacity. The sub-spindle has 11 / 15 kW (14.8 / 20.1 hp) and 4,500 rpm, and passes Ø51 mm (Ø2 in).

Be aware that no tailstock centre is available as a fallback: on the 2S series the sub-spindle replaces the tailstock. A slender shaft has to be held in the sub-spindle chuck or steadied.

The SL-60-2S weighs 7,800 kg (17,160 lb) and is 5,210 mm (205.1 in) long, against 6,500 kg (14,300 lb) and 4,400 mm (173.2 in) for the SL-50-2S. Y-axis travel on the optional version is ±40 mm (±1.6 in).