The client was an entrepreneur, with a background in vehicle refinishing and engineering, who had been developing a High Volume Low Pressure gravity feed refinishing gun for some time and had prototyped several variants.
The invention was innovative because the internal airflow was very 'clean' and had little turbulence. The spray pattern was excellent with high delivery and good coverage at less than 5psi. The benefits of the invention would be reduced paint and solvent costs with less overspray and secondary polishing.
The brief was to reverse engineer the internal configuration, develop a Refinishing Spray Gun around this and prepare a full set of manufacturing drawings for a small batch manufacture of fifty products.
The first stage was to develop the ergonomics of the operation of the valve and trigger and establish the optimum balance point for the paint pot and airline for the comfort and accuracy of the operator. This was done using traditional block models ballasted with weights. The feedback was crucial in determining the optimum cam profile on the heel of the trigger and the proportional opening of the valve.
The prototype was reverse engineered into 3D CAD. The client had previously retained a precision engineering machine shop. The CAD data and control drawings were issued to the machine shop to manufacture a prototype assembly. A rapid prototype of the outer casing was produced and the product adjusted until the design and drawings were signed off for batch manufacture.
The client wished to market the Refinishing Gun as a whole product concept and the brief was extended during the manufacture of the first batch to include the preparation of concept visuals for a storage cabinet and a service/automated wash station.