Results of workpackage 3 – Handling and Alignment

The main focus of work package 3 is the development of solutions for the automated work piece and tool handling in the field of micro and ultra precision machining. Several devices and test benches have been defined at the beginning of the project covering different processes and machines as well as the transportation issues 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.

Main results so far:

• The work piece carrier 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 an tilt motion of the chuck according the X- and the Y-axis. Three CCD cameras aim at reference marks of the pallet and determine the orientation of the work piece. After 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 of Fidia.
  
• An automated tool exchange system for a diamond turning machine has been realized and fully integrated into a ultra-precision lathe by the 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). As tool referencing systems a CCD camera and a tactile probe are used. The alignment unit is further able to pick up tool holders carrying diamond tools. The whole unit is operated by a Fidia numerical control.
  
• KU Leuven is developing a solution for the double sided machining of optical components by fixing the lens, even with free-form shape, using an UV-curable adhesive chuck. Therefore the clamping and the alignment as well as the flipping will be realized.
  
• 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 contribute strongly in the idea of Production4µ since they help to automate the ultra-precision machining processes. So far ultra-precision machining is characterized by a lot of manual effort for both the work piece alignment and the tool setting. In the remaining time of the project the developed systems will be further optimized for the serial production. Additionally, devices for the work piece alignment on rotational spindles and automated balancing for the tool exchange in fly-cutting processes will be realized.