Rotor is a speedy font. In 1929 K. Sommer designed a typeface for Linotype called “Vulcan”. Some years later they republished the typeface and called it Dynamo.
The early Vulcan design inspired me to do this new, faster typeface in two different “speeds”, meaning I gave the design two opposing slants on the slab-serifs. In order to make it more useful I drew two sets of each “speed”, one with the white speedtraces and one without. And of course I did give it an allover new look, but still kept it a very art deco kind of typeface.