Okay, let’s break it down. David has 35+ years of experience as a mechanical designer, which is a significant amount of time. The industry average for mechanical designers in the US, according to the Bureau of Labor Statistics, is around $60,000 per year. However, considering his extensive experience, I would estimate his hourly rate to be higher. Let’s assume an average of $100-$150 per hour for a mechanical designer with his level of experience. Since he’s working in the US, I’ll use that as a reference point. However, as he’s been working for 35+ years, his skills are likely to be more specialized, so I’ll adjust the rate downward to $125 per hour. This is still a rough estimate, but it takes into account his extensive experience and the industry average.