Hi there,
I'm a mechanical engineer with over 15 years experience in designing, modeling, prototyping and effective manufacturing of different products, ranging from consumer goods to alternative energy systems.
I could assist with your model (3D prototype) in a very professional manner.
I will take the work from your draft/skecth and I'll make the 3D model with components, including execution drawings with all dimensions and tollerances.
Base don your sketch I'll make a draft of the model, and together we'll finish the model.
I'll provide you the 3D model and its components in different CAD format (iges, stl, step, etc), 3D pdf, execution drawings and renderings, so whoever you'll find to manufacture, will be able to start with no issue at all. In the case that your manufacturer still find issues, I'll be here for help and assistance.