5-axis CNC machining process of a vehicle upright

Abstract

Computer Numerical Control (CNC) machining is a widely adopted subtractive manufacturing process. It has made traditional machining significantly better due to its efficiency and precision, improving exponentially as the technology advances. However, 3-axis CNC machining still has many limitations with parts having overhangs and blind features requiring manual re-orientation between setups. Hence, 5-axis machining is required for demanding designs to accommodate complex features. This is because 5-axis machining has the ability to continuously alter the workpiece to adapt for the accessibility and design contours of tools. However, the benefits of 5-axis machining come with added complexity and operational challenges. These challenges are secure work holding without excess material usage and keeping features accessible or choosing the appropriate tool to be rigid yet able to access these complex features. In this dissertation these challenges are emphasised due to the limited working volume in the Haas VF2YT fitted with a TRT160 trunnion attachment which enables two additional rotational axes to make it an overall 5-axis capable machine. However, this attachment also tightens the working volume and increases potential collisions between the spindle and this trunnion. This makes machining bigger parts difficult considering the additional work holding devices needed. Hence a strategic approach and well planned out machining was studied to machine the University of Malta Formula Sae race car uprights in the Department of Industrial and Manufacturing Engineering (DIME) labs. This dissertation challenges the Haas VF2YT with the TRT160 restrictions by evaluating different machining toolpaths and discovering different work holding devices and techniques. Using a virtual replica on Fusion360 to plan, create, and visualise toolpaths to detect issues like collisions and adjust accordingly. Experimenting with test parts, to vary parameters and measuring them to compare to the required tolerances. Ensuring that final machining of the upright was done aligning with its specifications. This gives insights into achieving multi-axis machining for complex geometries on compact machines, showcasing adaptable techniques to mitigate spatial and mechanical limitations in small-scale CNC setups.