A customised positioning system from LG Motion for a leading UK research institute.
Diamond Light Source, the UK’s national synchrotron science facility approached LG Motion to design and manufacture a customised Beamline Detector Positioning System.
The system illuminates miniscule crystal samples with an X-ray beam and detectors are positioned to capture scattered light that reveals the complexities of protein structure and their functions.
The objective was to increase flexibility and research throughput on the I24 beamline. The design called for an XZ positioning rig able to load multiple detectors up to 280kg mass with a volume of around 1 m3 over a 1.55 metre horizontal and 0.85 metre vertical travel range.
The Solution
The custom-built detector positioning system is based around precision linear rails with integrated linear encoder and precision ground ballscrews that are connected to a servo motor via flexible couplings. The vertical axis includes a safety brake and further in-line planetary gearhead reduction to ensure that it does not back-drive under power off conditions, even if the fail safe brake is disengaged for any reason. Both axes also include datum and over-travel limit switches as a part of the specification.
The 280kg detector load is evenly distributed on the horizontal stage carriage plate using a welded steel framework with four vertical precision linear bearing rails which guide the vertical translation of the detector mounting platform.
Each horizontal rail has three bearing carriages that support the upper moving horizontal stage carriage plate which is approximately 1000mm square and 20mm in thickness. The large base plate of the detector system was bolted to the experiment hutch floor after some precision laser alignment, levelling and grouting on installation.
The vertical axis uses one pair of bearing rails utilising three bearing carriages, with on the opposing pair just one carriage, this design is much preferred to a more conventional dual bearing arrangement for overhung loads, but this design allowed the use of smaller linear bearings and simplified the power transmission mechanics to be used.
Tel: +44 (0) 1256 365600
info@lg-motion.co.uk
