Large Diamond Turned Parts
Cranfield Precision has successfully cut a shallow optical surface in aluminium for the Very High Energy (VHE) Gamma Ray Astronomy Group at Durham University. Ordinarily, this would not be unusual, but the workpiece diameter in this instance is 700mm.
The finished surface has a radius of curvature of around 30metres putting difficult control constraints on the servo system. The large Diamond Turning Machine LDTM has been producing optical quality components for more than 20years and is still capable of delivering exceptional results on workpieces up to 1.4metres in diameter.
A recent CNC control system upgrade has enable more complex forms to be produced including aspherics. The secret of the success of the machine is the ultra-precision air-bearing rotary table and the sub-micron repeatability of the linear axes. More work is planned later this year.