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Build a prototype mold in a week?
Yes, that's possible when you combine three non-traditional processes: Stereolithography, Abrading, and EDMing. Lead times can be dramatically reduced.
Hausermann, in a joint project with an automobile manufacturer and a leading rapid prototype shop, produced an aluminum prototype mold in less than two weeks.
The manufacturer needed parts made of the same material to be used in production for crash testing.
The designer produced prototype parts using stereolithography. However, to produce parts in the production material, an aluminum prototype mold is needed. Because of the large size and fine detail (small rib sections), this type of mold would normally take months to build.
The prototyper supplied Hausermann with the SLA part - nested in a parting line board. In less that a week, Hausermann cast the cavity side abrading die off the nested part and machined it flat and square before separating it from the parting line board; a second (injector side) abrading die was cast off the cavity side abrading die with the SLA part still nested in it. (This way part match and parting line seal-off is insured as the abrading dies are cast off each other with the part encased in them.)
After the abrading dies cured, they were set up in an abrading machine and simultaneously abraded both electrodes. Concurrently, we were grinding the aluminum blocks square and rough milling the impressions.
Each mold half was set up in a separate EDM. It took only a couple of days (running unattended overnight) to EDM both impressions and parting lines to a finish that required no polishing. One redressing (re-abrading) of the electrode was needed. The re-abrade time was only a couple of hours and didn't affect lead time
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