Using rapid prototyping technologies requires design software. This software allows you to design a part on a computer, controlling its shape and dimensions and making design adjustments based on the chosen manufacturing technique.
However, whether you are able to develop a feasible digital design probably depends on your level of design and engineering experience.
Those without prior CAD experience might need to consult a professional product designer to fulfill the design brief. Professionals know how to manipulate the software, and they also know whether a design can realistically be fabricated using hardware like a CNC machine. (We often receive designs that are not manufacturable because they do not take into account factors like draft angles, parting lines and overhangs.)
Those who do have CAD experience — product designers, R&D specialists, etc. — can create a digital design using their design suite of choice then export it to a machine-readable format such as a STEP file (for CNC machining, etc.) or a Mesh file (for 3D printing etc.).
The digital file is the most important stage, but you must also specify a desired material, quantity and surface finish (if required) to the rapid prototyping company.
In many cases, you might prefer to send off Requests for Quotation (RFQs) to several rapid prototyping companies in order to compare quotations in terms of price, proposed lead time and the reputation of the manufacturer.
Once a satisfactory quotation has been received, you can finalize the order with the rapid prototyping company, who will use your digital design and order specifications to commence production.
The prototypes will be shipped to you once production is complete.