Work Package 3: Handling and Alignment

In work package 3, the reproducibility in handling and aligning work pieces and cutting tools in micro and ultra precision machining processes is improved by the automation of the alignment process. It significantly increases the machining accuracy beyond the submicron level. Standardized pallet interfaces ensure a sub micron reproducible clamping of work pieces on active chuck systems. An automated tool exchange is implemented for diamond cutting, micro milling and grinding tools.

The main focus of work package 3 is on the development of solutions for the automated work piece and tool handling in the field of micro and ultra precision machining. This covers various ultra precision processes and machines as well as the issue of transportation of partly or ready machined work pieces. The work pieces are carried on pallets which can be detected via reference marks and are identified with the help of RFID chips throughout the entire process chain. Thus, the pallets are the links between different coordinate systems of machine tools and metrology systems.

The palletization system which is used in work package 3 is based on a pallet system of System 3R. The development of the new nano chuck system, called »MacroMatrix«, enables sub-micron referencing precision. Due to the pallet dimensions (Ø 133 mm) large work pieces can be clamped with great stability. The targeted referencing precision is designed to be below 0.3 µm. With an overall system height of just 70 mm the »MacroMatrix« is especially suitable for the miniaturized precision machines which are the latest developments in precision machining. Furthermore, a vibration damped chuck has been developed and optimized in cooperation with the KTH in Stockholm.

Fraunhofer IPT developed an active work piece alignment device which adjusts the work piece after clamping a pallet. A flexure joint body which embeds a System 3R »Macro« chuck is articulated by four piezo actuators to realize a tilt motion of the chuck along the X- and the Y-axis. Three CCD cameras are targeted at reference marks of the pallet and determine the orientation of the work piece. Following the angular alignment, further deviations can be forwarded to the machine tool control for compensation. The active alignment device is managed by a numerical control provided by Fidia.

An automated tool exchange system for a diamond turning machine has been realized and fully integrated into an ultra precision lathe by Fraunhofer IPT. The alignment unit is placed on the Z-slide and allows for the adjustment of the cutting tool in three directions (A-, B-, Y-axis). A CCD camera and a tactile probe are used as tool referencing systems. Beyond that, the alignment unit is able to pick up tool holders carrying diamond tools. The whole unit is operated by a Fidia numerical control.

KU Leuven has developed a solution for the double sided machining of optical components by fixing the lens, even if it is free-form shaped, using a UV-curable adhesive chuck.

The secure transportation of optical components is ensured by a box-carrier designed by KU Leuven. The box is capable to carry one pallet of System3R and is closed by a sealed lid.

The developed results and solutions strongly contribute to the idea of Production4µ since they help automate ultra precision machining processes which were characterized by a lot of manual effort concerning the work piece alignment and tool setting until now.