A Bath University student has developed a method of rapid prototyping sheet metal parts. The low-cost technique also promises to be cost-effective for producing small batches of sheet metal components.
Until now, although the shape of a sheet metal component could be modelled as a three-dimensional block by conventional rapid prototyping systems, there has been no way to make parts directly from CAD data files.
Dan Leach, a mechanical systems, design and manufacture student, developed the new technique as part of his final year MEng research project. The work was one of the winners in this year’s INA Bearings Engineering Student of the Year Competition.
The method uses a CNC milling machine and a specially designed fixture that holds a piece of aluminium sheet rigidly along its edges.
The machine is fitted with a simple tool with a spherical end in place of a cutting tool, which rotates in contact with the aluminium sheet, and plastically deforms it to a profile determined by a CAD file. Grease is used to lubricate the sheet metal surface during the process.
Sheet metal parts can be made in a matter of hours to an accuracy of around 1mm. Leach found that a tendency for the component to deform excessively at the edges of could be solved by reworking it on the reverse side.
Leach’s supervisor, professor Alan Bramley, head of design, manufacturing and materials at Bath, says the university is now looking for an industry collaborator to develop and commercialise the process.