IRAM, Plateau de Bure, France Until now seven IRAM-telescopes were built. Six are set in the Plateau de Bure near Grenoble in France and the seventh is set in La Silla in Chile. The reflector diameter is 15m. The six telescopes in France move on two railing systems. Because of this system it's possible to increase the measuring sensitivity that much that it's that high as you'd have one telescope with the diameter of 760m. Radioteleskcope at the Plateau de Bure near Grenoble(France) Boehm produced different components for telescopes. Usually Boehm gets design studies and sketches. Boehm does design work and drawings, produces the parts and assembles them. Actuator The Actuator consists of a gearmotor, which drives the metric spindel through a spur gearing. Position is controlled with an incremental encoder. Typical repeatability is 3µm. The maximum allowable axial load is 1000N (cycled). More than 6000 of these actuators have been produced by BOEHM. Even under adverse environmental conditions, with temperature changes from –20°C to +20°C, no mechanical failure has occurred since 1985. Up to 5 actuators are mounted under each reflector panel. A reflector consists of 176 panels. 848 actuators are mounted to each reflector. The actuators are remote controlled. Reflector backside; view of panel - actuator - strut. The lactuators connect carbon fiber struts to the reflector panels. Subreflector Actuator 4 subreflector actuators move the l subreflector. High precision is achieved with spindle bearings and a rollerscrew. Repeatability is better than 1 µm.