Welding Positioner Spindle

Overview: My undergraduate thesis involved the design and fabrication of a benchtop welding positioner spindle.

Abstract:

The spindle of a benchtop welding positioner is designed to meet a defined set of specifications. These particular specifications consist of dimensional optimizations for spindle height and thru bore diameter and performance requirements, such as speed. Preliminary static analyses are conducted on the subsystems with the heaviest design consideration to ensure they meet the spindle’s requirements. The design takes into account the spindle’s manufacturability, assemblability, components’ overall cost, bearing protection, grounding cable path, and more important aspects. Ultimately, a welding positioner spindle is designed, and a prototype is manufactured to investigate the outcome of the design.

Development Process:

• Reviewed and refined preliminary design of the spindle assembly

• Developed a motor configuration heat map based on motor torque, speed, and resolution for varying pulley gear ratios with dimensional requirements to inform motor selection and specification of the pulley power transmission.

• Calculated loading forces to inform bearing selection

• Designed and ground custom lathe grooving tools to overcome setup interference constraints with the available tools.

• Turned parts up to 175 mm wide on the lathe by machining features like bores, custom-size internal & external threads, and grooves

• Assembled mechanical parts with fasteners and MIG welding

• Designed electronics breadboard for motor control

You can view my final paper here. 

I successfully assembled and operated the spindle. Future work on the project would have included further review on the manufacturing tradeoffs for pursuing such a short and wide design, load testing at various angles to determine the workpiece limitations for the device. Overall, I'm grateful for my deeper intimacy with the lathe and still completing the project despite contracting COVID a over a week before the deadline.