Slashdot Mirror
Making Casings for Prototype Electronic Devices?
kiddailey asks: "I'm working on a project for self-enrichment that involves creating a working prototype of an electronic device. I've made a model of the basic shape of the device out of Sculpey (tm) and want to use it as a mold to make the actual plastic housing that I can then insert the electronics into. Has anyone done something like this before? Is there any way to achieve this without a significant R&D buget?"
I generally use wood, light, strong, cheap, but labour intensive to shape. And flammable :)
-Yarn - Rio Karma: Excellent
You could always use that as a 'plug' (male model) from which to make a female mold (out of glassfibre or plaster).
You can then make a thin shell casing from the female mold, in glassfibre or carbon (looks _very_ cool).
Hydrocal is a hard plaster/cement type compound that works _really_ well for short run molds, or for one-off parts, generic plaster works well. If the shape is complex, eg. has undercuts, then you'll need to make the mold from silicone. Check out Special Effect Supply, they seem to stock a lot of the stuff.
Once you have the mold, you can then lay up a part using polyester (Yuck!) or epoxy resin and glass, carbon or kevlar fabric. Glass fabrics are now also available in colors (I've seen red, silver and blue) if you don't want to paint the final part. Another option is to cast the part using a polyurethane resin, (try ProCast
)
You will probably have to make a multi-part mold in order to define a wall thickness, though.
Maybe check out FibreGlast for some ideas.
There are _much_ more elegant ways to do this (eg. CNC machining), but molded glass or polyurethane is probably about the easiest / cheapest method of prototyping this sort of thing. With a bit of effort, you can get _really_ professional looking results.