First prototypes are for you alone. No one else need see them, so they can be made from any suitable cheap materials. Their purpose is:
If you can, use computer aided design (CAD) for much of this stage. CAD can save significant time and cost, and may provide you with much additional data that might be difficult or impossible to collect from physical prototypes.
It is advisable not to move beyond first prototype stage until you have done all the problem-solving and design refinement you can. This may be frustrating, but solving problems or redesigning your idea at a later stage is likely to be much more difficult and expensive.
These are the prototypes which you will use to demonstrate your idea to other people - in particular, to potential investors or licensees. They should look and perform as much as possible like a finished product. The main reasons are:
You may need professional help to produce a finished prototype: for example, from a product designer or a company that specialises in prototypes. The cost may be worthwhile if it enables other people to understand more fully (a) the potential of your invention and (b) your own professionalism and commitment.
However, if you use professionals try to avoid unnecessary costs. Designing and making an entirely original prototype will be expensive. Using at least some standard industrial components, or parts ‘borrowed' from existing products, may be much cheaper. You must set a budget that balances quality and affordability, and you should always question any proposal that substantially increases cost for only a marginal gain in function or appearance.
Without doubt, the best form of finished prototype is a saleable product. You can prove that your idea sells, even if only on a small scale, and you have a supply of samples to speed up evaluation by companies. This strategy will not be suitable for every invention, but it may be worth considering if there is relatively little difference between the cost of a single prototype and the cost of a trial batch of, for example, 100 further units. In most forms of manufacturing, the greatest cost is the set-up; the products themselves cost relatively little.
If you cannot afford a high quality prototype, an acceptable alternative may be a combination of the best of your first prototypes (to demonstrate performance) and a non-working model (to demonstrate appearance). For the model you can use any cheap workable material - for example, painted wood to represent plastic.
A video may be essential support material if:
Edit the video to no longer than a few minutes so that it does not occupy too much time during a typical first meeting of 30-45 minutes.
Video can be easily copied and will count as disclosure, so be careful to ensure that (a) your idea has adequate legal protection and (b) you do not allow unauthorised viewing and copying of the video. The video itself should be protected by copyright (Part 5).
Additional material that may help you present your idea could include: