I have worked with several inventors in the past refining their ideas into patentable inventions, and then finishing the detail design and fabricating prototypes. I teach engineering design and engineering graphics for a living. I am well qualified with BS, MS, and PhD degrees in mechanical engineering. The price of $100 is based on $50/hr for 2 hours. I will be happy to negotiate either on an hourly basis or for the entire job turn-key. Feel free to contact me via the PMB with any questions. I look forward to working with you!