Brunsviga A

Stepped drum machine (1905)

After the start of production of Brunsviga stepped drum machines in 1892, the chief engineer Franz Trinks began working on improvements to Odhner's design. This led to the production of the 18-position Model A as early as the following year, which made it absolutely necessary to extend the hand crank: with the short crank of the original model (cf. 1892/1893), one hurt one's right hand when the carriage was extended to the right. Model A differed from Model B in the larger capacity of the movements: 9 x 10 x 18 instead of 9 x 8 x 13. It was therefore suitable for calculations where a large number of digits or a high degree of accuracy was required, for example in the technical-scientific field. While FDM 6402 is a very early example of model A (probably from 1893), the present machine contains the improvements in equipment, which were made until 1905, mainly by Franz Trinks, i.e. the crank reversing lock (lever top left), the EW-clearance (wing screw left side), a direction of rotation indicator and decimal slides fixed on rails. In the result movement, the tens carry functions over all digits, the revolution counter has no tens carry yet. The model A was built from 1893 to 1920 in 3655 copies