Design project

I need some graphic design. I am an amateur inventor, and I have had some success selling my invention locally. I would like to expand and offer a digital depiction of the item. Since I have been making these items in my small machine shop, I have an issue with repeatability so I would like to also have some shop drawing with measurements and machining instructions. This is a start up company and I am financing thing myself. That being said I need to keep a low budget.