email: tony@lathes.co.uk
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LORCH Precision Screwcutting Lathe
Type B30LZS & B30LZ

Lorch Home Page

A manual is available for the Lorch B30LZS

Other Lorch Sales & Technical Specification
Brochures can be purchased on-line here

Founded in 1885 - and trading under the names "F.Lorch", "L.S.& Co." and "Lorch, Schmidt & Co." - Lorch was a German precision machine-tool company finally driven out of business when, in November 1976, the merchant bank supporting it withdrew support. From the 1960s, into the 1970s, the final large lathes listed by Lorch were 120 mm centre height by 560 mm between centres, infinitely variable-speed drive B30LZS with a 2-speed, 1.5/2.2 kW motor that gave a spindle range from 47 to 2100 r.p.m. and the conventional B30LZ with a three speed, 0.8/1.2/1.8 kW motor and a speed range from 70 to 1400 r.p.m. 
Both lathes - in the then 80-year Lorch tradition when launched - were beautifully constructed machines fitted with super precision, adjustable, multi-surface plain headstock bearings; a 30 mm spindle bore; a through collet capacity of 24 mm; a particularly smooth running headstock driven by a wide flat belt; compound slide-rest feed screws fitted with angular-contact ball bearings to absorb radial play and very large diameter, precisely-engraved satin-chrome plated micrometer dials locked by non-upsetting face screws and reading to 0.01 mm; the top slide had a generously long travel of 150 mm ( 5 mm longer than that of the cross slide) and could be swivelled 45 each side of central.
Both longitudinal and traverse power feeds were equipped with an electro-mechanical clutch mechanism that allowed precise and automatic pre-set disengagement (to within a claimed accuracy of 5 microns) while the screwcutting and feeds gearbox, that contained 50 hardened and ground gears running in an oil bath, provided some 75 different ratios. From the box it was possible to select 20 rates of longitudinal and traverse feed, 34 metric pitches and 25 inch without the need to alter any of the changewheel drive. Changes of the feed rate could be made without stopping the spindle and, by the substitution of a single changewheel, a further 24 Module-pitch threads could be generated. Sliding feeds ranged from 0.017 to 0.60 mm per revolution of the spindle with surfacing speeds set to be twice as fine. The 5 mm pitch leadscrew, machined with a high-precision thread, ran in a shielded recess along the front of the bed where its location, closer to the cutting tool than if mounted conventionally on outside hanger bearings, not only protected it from the wearing effects of swarf and dirt but also helped to reduce the twisting effect on the carriage as a thread was cut.
Of conventional form, the tailstock was locked to the bed by an eccentric cross-clamp and held a No. 3 Morse taper spindle with 90 mm of travel locked by a proper "split-barrel" compression fitting. Engraved (for export markets) with both metric and inch ruler graduations, the spindle was also fitted with a zeroing micrometer dial.
A very wide range of accessories was offered - so vast that a separate catalogue was published to illustrated them - amongst which were alternative tailstocks, a hydraulic copying attachment, steadies, a variety of standard, 4-way and quick-set toolholders, numerous chucks and faceplates, toolpost grinders, dividing attachments, a coolant system, light units, hand T-rests, collets and a milling attachment.
Occupying a space approximately 1700 mm long by 480 mm wide the lathes stood 1150 mm high and weighed - depending upon the equipment fitted - around 800 kg. The standard paint finish was a green to the specification RAL6011.



Both longitudinal and traverse power feeds were equipped with an electro-mechanical clutch mechanism that allowed precise and automatic pre-set disengagement (to within a claimed accuracy of 5 microns)



Lorch Home Page

A manual is available for the Lorch B30LZS

Other Lorch Sales & Technical Specification Brochures can be purchased on-line here

More information about Lorch Lathes is contained in various Manuals, Parts Lists
and well-illustrated Sales & Technical Specification Brochures and can be purchased on-line here


LORCH Precision Screwcutting Lathe
Type B30LZS & B30LZ

email: tony@lathes.co.uk
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