Star Prototype manufactures prototype crystal clear PMMA/Acrylic and PC components for many industries including the automotive sector. PMMA/Acrylic is notoriously difficult to handle because it crazes, cracks, and bends very easily. It must be handled with great care. Polishing PMMA is also very time consuming.
Star Prototype had just 10 days to CNC machine and polish 6 complete sets of crystal clear lenses for the new Jaguar CFX. The project was delivered to the UK in under 2 weeks and for less than half the price.
Star Prototype used the highest quality imported European materials and expended hundreds of hours in manual polishing. The longest component measured 1.2 metres in a single unfabricated piece.
Click on pictures above to see the CNC machining process for lenses...
Step 1: cut a block of imported acrylic oversize by about 30mm. Step 2: CNC machine the concave B surface first. Step 3: fill the B surface cavity with plaster. Step 4: machine the plaster face and edges as datums. Step 5: turn over and reference from datums with probe. Step 6: CNC machine A surface. Step 7: after machining the only thing holding the component to the machine bed is the plaster. Remove the part including plaster from machine bed. Step 8: remove plaster with solvent. Step 9: primer paint the part this allows the polisher to know when he has polished/cut down to the depth of the machined finish. Step 10: polish until crystal clear ensuring that sharp edges remain sharp and that the polishing is done evenly.
Click images below...