On 04/19/2013 12:30 AM, Gregg Eshelman wrote: > --- On Thu, 4/18/13, Kent A. Reed <kentallanr...@gmail.com> wrote: > >> From: Kent A. Reed <kentallanr...@gmail.com> > >>> On 18 April 2013 08:48, Gregg Eshelman <g_ala...@yahoo.com> >> wrote: >>>> How are molds for plastic reflectors machined? They >> have a large number of sharp edged corner cubes. > >>> Possibly forged with a pyramidal punch? >>> >> Take a look at http://www.nissin-precision.com/english/Rrm.htm >> >> Regards, >> Kent > > Lots of little hexagonal pins with highly polished, three sided ends, all > bound tightly together. Used as is or an electroformed surface is made from > the pin masrer. Looks like metal is cast against the back side of the > electroform then machined to insert into a plastic injection mold. > > I make cast resin copies of reflectors and lenses for classic cars. With a > good original an RTV silicone mold can exactly copy the reflective quality of > the original lens. > > So now I know how the originals are made. >
> the machines that produce the molds are sink edm's the models may be hand made or just prints, but the molds are edm'd look at AGie, Makino, Ingersoll, or Mitsubishi websites for examples look at any large mold shop in Windsor CA to see it in action edm can make a near square corner ( .0002" corner and edge radii are common on good finishes) btw: 'mirror' ( optically reflective ) finishes are NOT the best EDM finishes possible, really really good edm finishes appear to be matte. tomp /tjtr33 ------------------------------------------------------------------------------ Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis & visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
