Build Plate Handling System Design for Wire EDM Compatibility
This report outlines the detailed design of a build plate handling system for a ROBOCUT a-c600iB Wire EDM by Team-24 as part of the University of Manitoba’s MECH 4860 Engineering Design. The National Research Council of Canada (NRC) is the client for this project. The NRC’s new Brookside facility in Winnipeg, MB has advanced digital manufacturing research capability which focuses on additive manufacturing as part of their research and development projects. The facility has recently acquired a Laser Powder Bed Fusion based additive manufacturing technology and a post processing technique that utilizes Wire Electrical Discharge Machining (Wire EDM). The parts fabricated from this particular additive manufacturing technique get welded on a build plate and are required to be separated. The current process of handling a build plate of up to 125 kg after the 3D printing process is unsafe and a difficult task for the operator. The NRC aims to improve this process and enhance the safety and user experience in handling a heavy build plate and hence, challenged the student team to produce a viable solution. A secondary objective of this project was to provide a solution to fixturing the build plate inside the Wire EDM. However, due to time constraints and discussions with the client, the team decided to focus on the primary objective of orienting the build plate in the Wire EDM cut direction, which also includes the loading/unloading of the build plate. After brainstorming along with regular meetings with the client, the team developed a design that could change the orientation of the build plate and transfer the build plate inside the Wire EDM in a safer manner than the existing solution. The team divided the requirements that the solution must perform into different components i.e., Gathering, Rotating, Transferring. Each of these components require significantly less amount manual lifting and manipulating of the build plate and decreases operator’s risk of injury or damage to the build plate or parts. The deliverables of the project are a CAD model of the final design from SolidWorks, preliminary engineering drawings of the final design, a tipping/deformation analysis of the handling system, a Bill of Materials (BOM), and the standard operating procedures. The project team introduces a clamp & brackets system to pick up the build plate, a manual rotary table to satisfy the requirement of presenting the build plate vertically for machining, and a modified KLETON Hydraulic Stacker Model No.397 to transfer the vertical build plate into the Wire EDM. The FEA of clamps gives a Factor of Safety (FOS) of 8.78 and a clamp FOS of 1.80. The two major modifications to the stacker are changing the original lifter arms to a single center-located boom to support the build plate and changing the legs of the stacker due low clearance and maneuver around the iii supports of the Wire EDM. The FEA of the modified boom results in a FOS of 5. An additional support is introduced for the clamp, the design satisfied the marginal target metric FOS of 2 set by the project team. The entire project costs $5,994.80 CAD, which is less than the budget allocated to the team, $6,000. The estimated of the raw materials is $1,956.57 CAD whereas the purchasing of off-the-shelf products is $4,038.23 CAD. For future recommendations, the project team recommends an addition of a telescopic boom, a linear actuator to operate the telescopic boom, and a dynamic tipping analysis of the hydraulic stacker.