In the same vein as Staedtler’s Galileo, the 1990s also saw Rotring trying to reinvent the compass, in particular the spindle-adjustment master bow. The resulting design is unusual not only in appearance, but also because it incorporates two patents taken out by Rotring under their own name. Of the dozens of Rotring patents only a handful were for compasses, largely due to the fact that the majority of Rotring compasses were made for them by firms such as Riefler and Haff.
The earlier patent from 1990 is for a double-geared head, with the inventor named as Dietmar Seelig; he was also co-inventor of the subsequent 1992 patent for a compass with diagonal quick-setting spindle, alongside Koerth Reimar. Seelig was head of the eponymous drawing instrument manufacturer based in Emskirchen, Germany – Reisszeugfabrik Seelig GmbH & Co. KG – that produced compasses for Rotring and is still in operation today, selling compasses under the SEMA brand.
While the first patent clearly follows in the footsteps of Lotter’s early 20th century geared head, it is the second that stands out as a radical departure from the tried-and-tested master bow design. The object of the patent was deceptively straightforward: to create a compass in which the lateral protrusion of the spindle is minimised when the legs are closed, allowing it to take up less space in a case.
Ironically, the packaging for the resultant Rotring Centro (Art. 530 111) displays the compass half open, presumably to show off the patent spindle at its jauntiest angle.
The other hard-to-miss innovation is the beachball-like thumbwheel in place of the usual knurled metal wheel. This was not mere flamboyance, but a functional attempt to address the issue of the spindle’s constantly changing angle at different settings. The extent to which it manages to successfully resolve this ergonomic challenge is debatable, but it’s hard not to smile at such a spirited design solution.
While both the Galileo and Centro are surprisingly well built for mid-range models, the Rotring comes out on top in terms of usefulness. As well as having the quick-setting mechanism that the Galileo so badly needed, it also offers knee joints to both legs and a removable pencil point with standard 4 mm shank, essential for drawing with Rotring pens.
Like the Galileo, the Centro was later offered in a range of school-friendly multicolour paint schemes. I am not sure how long it was sold for, or in which markets – the 1990s represent a significant gap in my Rotring catalogue collection – but the packaging of my example predates the 1998 acquisition of Rotring by US firm Sanford.
Certainly the Centro range of compasses with Seelig’s geared head continued to be sold by Rotring until at least 2017, but only with a standard horizontal spindle design. Although not exactly a rare compass, the diagonal spindle model is not often seen today, which perhaps reflects low sales volumes. Whether this was due to their pricing, or perhaps a more fundamental distrust of the eccentric spindle design, is difficult to say.