Similar to lathes by the Karger Company, the Dresden-manufactured Auerbach was another high-quality German maker who, beginning in 1890, made a range of lathes including several beautifully constructed, precision plain-turning types. The first example, shown immediately below in the colour photograph, is fitted with chase screwcutting using a sliding headstock spindle - the method of operation being identical to that described in detail here.
In its first year of production, the Auerbach factory employed just twenty workmen, a number that had grown to 160 by 1926 - though immediately after WW1, staff reached a record high of 220. In the early years, considering the limited size of the works, an impressively large range of machine tools was offered, including capstan lathes with either vertical revolver or standard horizontal turret heads, special machines for electric-motor armature work, ordinary sliding and screwcutting lathes from 135 to 295 mm centre height, precision plain-turning, hand-operated lathes, production revolver-turret lathes intended for fine optical work, a number of simple horizontal and universal milling machines and one multi-spindle boring machine.
By 1910, a limited-liability company had been formed (G.m.b.H), and production was rationalised around far fewer models, allowing more economical production methods to be employed. In 1912, a revised range of vertical revolver lathes with spindle bores from 30 to 70 mm was introduced and proved immediately popular. Following the First World War (1918 onwards) the model range was revised once more; the new models including capstan lathes fitted with vertical revolver turrets, spindle bores from 12 to 40 mm diameter and with two different shifting systems for chuck work and long bar work  Also in production was a range of ordinary horizontal turret lathes with spindle bores from 20 to 50 mm designed specially for chuck work. These latter modeks, for the English and perhaps other export markets, probably carried the name "Hille" - an English catalogue dated 1935 shows machines displaying such a nameplate.
In addition, a series of very special precision capstan lathes from 20 to 100 mm spindle bore - so-called Optical-Capstan types - with 125 to 155 mm centre heights and intended for optical, mechanical and electrical parts made not only in metal but also Galalith and Bakelite (both early plastics), hard rubber, various vulcanised fibres - and even coal. All these revised models were built in large numbers and became the mainstay of the company's profitability during the following decade. However, the long-established precision plain lathes also continued in production - as did a range of semi-automatic and double-spindle milling machines, geared-head drills and various interesting 'specials', including a water tap grinding machine and, for use in precision workshops, a high-speed milling machine with automatic or hand-feed control.
Do you have an Auerbach of Hille machine tool, or literature about them? If you do, the writer would be interested to hear from you..