Studer Model OB The Studer OB was the direct successor to the model OA and was produced from the mid 1930s through to the early 1970s. The OB could accept work up to 400mm long and 100mm in diameter. Around 1500 machines were produced and around 160 were imported to the UK with most machines destined for government bodies such as Royal Ordinance and Royal Mail research departments. By the 1950s the design of the OB was looking rather antiquated, Studer had pioneered the use of hydraulic table transport in 1939 but the OB continued to use the mechanical drive developed in before the Great War. What ensured the longevity of the OB was its phenomenal versatility. Not only did it have the conventional table and wheel-head movements, but also a secondary wheel-head compound slide with screw or lever operation. This slide was mounted on a swiveling base allowing the wheel-head, which could also be independantly angled, to be fed into the job at any angle. The wheel-head could also carry a second smaller wheel on the right hand end of the spindle further increasing the versatility of the machine. A wide range of accessories was available including various work-heads accepting Schaublin W20 collets, internal grinding attachments, work steadies and small part grinding attachments. The versatility of this machine and its compact size continues to make it useful for certain industrial applications today. One firm I know of has a number of OBs, reconditioned at great expense, used in the production of specialist tungsten carbide tools. GEPY also have a number of OBs employed in the production of their excellent revolving centres and precision spindles. I have a very well equipped OB in my own workshop which is employed in the reconditioning of other machines. Illustration showing compound wheel-head slide Internal grinding attachment