2x Kleppek Machine time T55 Machinenzeit slide rules 1930 Germany

This is an interesting piece of slide rule development. Two slide rules by Walter Kleppek. The earliest one is hand made in wood, covered with metal printed scales. It is only one sided and marked “Muster” as it was probably submitted to Muster office (like the patent office but specifically for devices). The sleeve it is in is made in the same handmade fashion with same rivets. Most interesting is to see when held next to the 1960’s successor, the T55 also by Kleppek but more professionally made in the GDR for distribution in large numbers. The black on white (part II / Teil II) is a redesign of the 1930’s version and combined with a machinetime site (red on white). All slide rules have 2 seperate sliders and there red on white side also has an additional cursors. The original 1930’s version did not use a cursor and neither does the redesign (part II / Teil II) of the T55.  The T55 also comes with a complete manual, explaining all scales and their operations (in German). They measures ca. 25 cm and 30 cm or ca. 10 and 12 inches long. Check the attached video on how to work your vintage man tool : slide rule operation instructions!