iflog: Good, if you can make a drawing of an article, you have more than a naked idea and potentially patentable subject matter. There are other hoops to jump throught (e.g. novelty and non-onbiousness).
1. Do make good drawings. A specification of a purely mechanical patent is largely a description of the figures, with an added discussion of how to use the device. 3D figures are not generally allowed. But, if needed, you can - and most applicants do -submit different views, including cross-section and perspective. The number of views required depends on the complexity of the device (a “manufacture” in patentspeak).
2. The rules say that the USPTO can require a “working model”. But it is very rare that the Office does so. A working model might help win-over investors. But be careful. If you don’t make it yourself, you’ll be “disclosing” the invention to a third party. Have a confidentiality agreement (“CDA” as many lawyers refer to them) with the machine shop.
3. A well-written patent application properly describing and enabling the invention on file at the USPTO provides much greater protection than any CDA. In fact, many potential investors won’t speak with you unless you have one. They are afraid you’ll sue them later for stealing your invention. But at a minimum have a CDA.
4. Concerning how to proceed, funding, etc., the book(s) referred to by others will probably help.
5. Concerning invention promotion companies. If you choose to use one, DO research them before sitting down with them. Many inventors have gotten screwed. You can check the USPTO web site for complaints. You can also check to see how many lawsuits they are / have been involved in. Google Scholar might work, but this might be better done by a legal professional familiar with legal databases. A simple search of a database shouldn’t take more than an hour’s time to get a simple listing of civil actions. Look at it as insurance cost.
6. Good luck! People have made money via infomertials.
7. The above are general informational comments, not legal advice.