Okay, let’s tackle this. So Mark Mcnally has a mix of mechanical engineering and design skills. His experience in rapid prototyping, product design, and product development is valuable. Skills like Solidworks and Pro/Engineer are in demand. Location is San Francisco, which is a hub for tech and innovation. Mechanical engineers with his level of experience, especially in product design, typically charge around $100–$200 per hour. However, considering the high demand for product designers in the Bay Area, maybe around $125–$175 per hour. Some mechanical engineers with similar skills might average $100–$150. So I’ll estimate around $125.