A very late model in the Leinen lathe lineup, this splendid Model MLZ4 STG was built in 1984 and so manufactured just before the Company stopped producing larger machines. In the considered opinion of an experienced owner, this was the best of the small German-made high-precision toolroom lathes - and in some ways preferable to the equivalent Schaublin models such as the 102VM. Whilst the Schaublin was a fine machine, it lacked both the full screwcutting and feeds gearbox of the MLZ4 STG and power cross feed. Nor did it have the outright capacity - or such a modern feature as carriage-mounted controls. Today, the Leinen is also less well known and hence better value on the used market.
Fitted with a single-speed 380-volt, 50Hz 3-phase motor and a two-range variable-speed gearbox, the transmission of the MLZ4 STG also included adjustable clutches and a smooth-running final drive flat belt (the drive system being much more like the larger DLZ models than the earlier MLZ types). Including backgear, the speed range was a very useful 25 to 3100 r.p.m. with a powerful spindle brake fitted as part of the standard specification. The action of the brake was so effective that it even allowed threading up to a shoulder without the danger of overrunning.
The screwcutting gearbox provided - with the use of additional transposing changewheels - metric, inch and MOD pitches with power feed in both longitudinal and traverse directions and adjustable, automatic knock-off stops on both directions.
The tailstock has the expected No. 2 Morse taper socket and the lathe - which weighs around 600 kg, has a centre height of 130 mm, takes 500 mm between centres and is fitted with a metric-graduated leadscrew and micrometer feed dials. The spindle nose is of the DIN-55027 / DIN-55022 / ISO 702/III size 4 and equipped with a high-quality 120 mm Rohm 3-jaw. The lathe shown has survived complete with its maker's tool cabinet, a set of B25 collets (1 mm to 22 mm and square) with drawbar, a travelling steady, a Swiss-made Multifix quick-set toolpost as well as the original very simple clamp type..