What moldable metal alloys would fit best for a housing for a consumer gadget?

Cynically, I would say the plastic of your choice plus metallic paint or a vacuum plate metallic finish. Or for really premium looks, plastic with embedded metal powder.

Do you have any samples of the kind of super-zoot thing you want to emulate?

I think any real metal that you could choose would either require painting for corrosion resistance, would increase your BOM cost significantly, or both. Most of the super-zoot consumer stuff that I know of that's obviously metal* is painted.

• and even then I'm not sure it _is_ metal, it's just obvious to me that it is...

Aluminum.

Steel. Possibley oil clay.

replying to Tim Wescott , Lea wrote: Tim

thanks for sharing your thoughts! the look we are trying to emulate is in fact rather straightforward - i attach the file to illustrate. once we tackle the first issue, we would like to consider color options as shown in the file

you would say, the embedded metal powder would do? we were considering the moldable metal alloys as an option, but weight and cost is big question marks

[IMG]

It's possible to injection mold magnesium alloy, more or less like plastics. I think it's normally painted. Useful for cell phone chassis/housings and such like. Thin walls & super-fine details, and probably some pretty premium tooling since there are patents and the temperatures are much higher than typical plastics:-

Parts made with this process are pretty impressive for tiny hand-held devices.

Of course you can die cast housings, but the die cast aluminum alloys don't anodize nicely at all, so again you're into paint, plating or some other coating.

You could machine the housing out of solid aluminum stock, in which case it could be finished and anodized directly.

It might be possible to nickel or chrome plate metal or plastic base, in which case you could get a satin or relatively shiny finish. You might be able to get a cold metal "feel" even on plastic with a thick plated base of copper.

replying to Spehro Pefhany , Lea wrote: Thank you for your thoughts and the link. We are considering as one of the options moldable magnesium alloys. I understand while raw materials might be more expensive than conventional plastics, there might be some advantages / cost savings in the manufacturing side.

Would appreciate a lot if you share your experiences with the cost implications (overall and raw materials) going moldable metals path

I'm pretty sure that those are thin stamped stainless steel shells over plastic. They could be anodized aluminum -- but I'd be quite surprised if they're not stamped or otherwise formed from sheet. If you have some of the physical items on hand, and you don't mind destroying them, I suggest you whack one or more of them in two with a hacksaw, and see how they're built.

(I should have thought of that method; really).

The sheet metal over plastic can look very good, and be very durable. Depending on what is used to glue things together it can also peel off in a distressingly short period of time, at which point it looks like cheap junk -- but I think that's avoidable.

Others have offered some good responses. I would say, though, that if you are serious about going into mass production, it would be well worth your while to consult an industrial designer who can help you weigh the pros and cons of the various options for your particular product. At some point you will need someone like that to create specs and drawings that a job shop can use.

You know that this is not an industrial newsgroup, but rather a group of individuals who work in metal as a hobby (the "rec." at the start is for "recreation".)

And for those who have the experience -- they may have retired a decade or two ago, and the world has changed.

Yes, there are some who have some experience in the commercial world (Not I -- I was an electronics tech for an Army R&D lab, and cost of production was never a consideration there. :-)

Sphero may be closer to what you need -- but he may or may not feel that he is able to judge costs of various routes. I'll let him speak for himself on this.

And remember -- free advice is worth every penny you pay for it. :-)

But the real kind of question to ask *here* is "How do I do this in my own home shop? I have the following tools which may help, and the following experience. I can borrow the use of these other tools, and some I might be easily tempted to buy."

My own first thought when you asked about mouldable (really -- castable) metals was Zamac (commonly called pot metal) -- but I have never seen such with a nice finish such as you need (any castable metals), so some kind of over-plating would be needed. And I have no experience in working with it -- just the problems of tools and parts falling apart several decades downstream. :-)

Magnesium adds the hazard of its serious flamability -- and being nearly impossible to put out once it is burning. Not a problem for

*you* as long as you are not the one casting it, but it probably will be reflected in the cost of the finished product. Someone has to pay the insurance costs for the process.

Good Luck, DoN.