First, all vacuum cast parts were made from CNC machine or printed on an SLA machine. We inspect the parts with a laser scanner (described below). The parts had a fairly rough surface when they came off the CNC/SLA machine, which is why we carefully polished the surface. After polished we painted the CNC/SLA parts until we were left with a beautiful smooth surface finish – just like on a real part. We call this finished part the master model.
Step 2: Inspection of Master Models
We inspected all CNC/3D-printed parts with a FARO (R) 3D laser scanner and then compared the scans with the 3D CAD models on our computer. On the deviation maps, which the 3D scan gives us, we can identify any potential areas which might be out of tolerance.
Step 3 – Making of the Silicone Mold:
Put model in a box, which we then filled with liquid silicone until the entire master model was surrounded by silicone. We cured the silicone overnight.
A specially trained craftsman painstakingly opened the cured silicone blocks with a cutter knife and carefully took out the master models. We were now left with the silicone mold:
The cavities in the silicone blocks copy the master model very accurately – including very intricate details such as textures or high-gloss surfaces. We then reused the mold to make subsequent units.
Step 4: Final Part Preparations:
After the part is hardened we carefully open the mold and evacuate the part. Naturally the process will leave a little bit of material in between the parting lines of the mold which we carefully remove by hand until the parts looks fantastic. One silicone mould life is 15-20 times.