3-D Printers

[Joe Farina]

If a 3-D printer is useful, and the material is temp. or humidity unstable for holograms, mold-making and casting in another material would be an option, using the 3-D printer object as the pattern.

Mold-making techniques have improved in recent years, to make things simpler. They have a two-part silicone putty (commonly available) which is simply kneaded in equal parts, and pressed on the part to be molded. Then the cast could be made in a wide variety of materials which are more stable for holography. A couple options for the casting material would be hard plaster (like Drystone, hard Hydrocal, Permastone, etc.), or a mixture of Portland cement and sand (artificial stone), though I don't know if this latter material can be used with silicone molds. Probably the ultimate (common) material with regards to holographic stability is clay which is dried, then fired (a kiln is needed). Clay can be press-molded in a mold, but the wall thickness of the clay piece cannot go beyond about 0.5 inch (not a serious limitation in my opinion). As a matter of fact, some of my component supports are firing right now in the kiln.

[jeand]

Hi Colin,
I've just purchased and builted a Velleman 3D Printer, the Vertex (K8400)
http://www.vertex3dprinter.eu/#specs
700€
Builted and tuned in 20 hours of works.
First tests seems very good. I'm still working with PLA but in a pair of weeks, I'll try ABS

First goals : mounts for optics, chassis for holo-printer, and why not a spatial filter.