Mechanical Engineer Interview

Can you explain your experience with designing rotary and linear gear systems for electromechanical actuators?

I have experience developing actuators from the group up, in mechanical design, prototyping, and experimentation, including manufacturing and production support. I am project lead of a compact torque dense line of actuators, and have moved this project from initial prototyping stages to full production with hundreds of units produced and in use

Your answer provides a solid foundation regarding your experience in robotics engineering, particularly in the context of designing electromechanical actuators. You have clearly articulated your involvement in the entire lifecycle of actuator development, from mechanical design to production. However, there are areas where you could improve the specificity and detail to directly address the question about rotary and linear gear systems.

To enhance your answer, consider the following points:

1. Technical Details: Include specific examples of rotary and linear gear systems you've designed, such as types of gears (e.g., spur gears, worm gears) and mechanisms (e.g., linear actuators or rotary servos). This would demonstrate your technical expertise.

2. Design Challenges: Discuss any design challenges you faced and how you overcame them. This illustrates problem-solving skills and familiarity with common issues in gear system design.

3. Tools and Software: Mention any design tools or software (e.g., CAD software) you used in the design process, which highlights your technical proficiency.

4. Outcome and Impact: Elaborate on the impact of your designs on overall project success, performance improvements, or customer satisfaction. This will help to quantify your contributions.

Your revised answer could look like this: "I have extensive experience developing rotary and linear gear systems for electromechanical actuators. As the project lead on a compact torque-dense actuator line, I designed both spur gears for rotary motion and lead screws for linear actuation. Overcoming challenges with efficiency and load capacity, I utilized CAD software to optimize designs, resulting in prototypes that exceeded performance expectations. Moving from prototyping to full production, we successfully manufactured hundreds of units that are currently operational, significantly enhancing our application's performance."

Rating: 3.5/5. Your original response is strong but could benefit from more detail and specificity.

Describe a project where you successfully improved the efficiency of an actuator system. What methods did you use?

Efficiency of an actuator comes primarily from the gear, which in a strain wave gear varies significantly in relation to temperature, so thermal management is critical. For this I implemented thermal padding, and the housing including mounting interfaces acts as a natural heat sink.

Your answer touches on an important aspect of actuator efficiency—thermal management. You correctly identified that temperature can affect the performance of strain wave gears, which can impact overall actuator efficiency. Implementing thermal padding and utilizing the housing as a heat sink demonstrates a practical approach to tackle the problem. However, your answer could benefit from a bit more detail and broader context.

To improve your response, consider the following points:

1. Project Description: Start by briefly describing the specific project or application related to the actuator system. This provides context and shows the significance of your contribution.

2. Quantifiable Results: Include metrics or results from your improvements—such as percentage increases in efficiency, reduced heat generation, or extended operational lifespan. Concrete figures can strengthen your answer significantly.

3. Broader Methods: Although thermal management is vital, consider discussing other potential methods that could have been employed, such as optimizing control algorithms, enhancing material selection, or improving mechanical design.

4. Collaboration and Challenges: Mention any teamwork, stakeholder interactions, or challenges you faced during the project and how you overcame them. This showcases your ability to work in a team and to adapt to difficulties.

5. Lessons Learned: Including insights you've gained from this experience adds depth to your response and illustrates your capacity for growth and understanding.

Rating your answer: 3/5. It has a solid foundation but lacks contextual richness and depth in results. Expanding your response can better showcase your skills and thought process in improving actuator efficiency.

How do you approach thermal analysis in actuator design, particularly regarding passive and active cooling techniques?

Active cooling requires additional subsystems and components so whatever you can do passively is ideal. Adding thermal padding to conduct head as well as minimizing the pathway for the heat transfer to the heatsink. After doing this for my project, I was able to improve heat performance by a few degrees

Your answer is a good start as it touches on fundamental concepts in thermal analysis and actuator design. You acknowledged the distinction between active and passive cooling techniques, which is important. By favoring passive cooling, you demonstrated an understanding of the trade-offs related to system complexity and energy consumption.

However, there are areas for improvement. It would be beneficial to elaborate on specific passive cooling techniques beyond thermal padding, such as the use of heat sinks, thermal interface materials, and design considerations that minimize thermal resistance. Detailing your approach to analyzing thermal performance—perhaps referencing simulations, calculations, or measurements you utilized—would enhance the depth of your response.

Additionally, mentioning the implications of temperature on actuator performance and reliability, as well as how to conduct thermal testing, would provide a more comprehensive view. Including the context of your project in terms of its scale or specific application could also strengthen your response.

Overall, your answer is relevant but lacks some technical depth and broader context. I would rate it a 3.5/5. By expanding on your methods and considerations, you could elevate your answer to be more thorough and impactful.