How do I make an aluminum object?

November 18, 2011 7:42 PM

I want to manufacture a small brushed aluminum object for a design project. I don't know where to start.

Trying to keep this simple, so the dimensions of the object are 1'x1'x1'. It is a very uncomplicated design. I can put the design on paper, but I don't know what type of organization I should contact in order to prototype the design, nor do I know what I should provide to the organization in order for them to create the object.

posted by uncannyslacks to sports, hobbies, & recreation (10 answers total)

Machine shop and ask them what sort of drawings they need.
posted by mollymayhem at 7:44 PM on November 18, 2011

Not too long ago, I had various DIY metal project-related questions, and I did a AskMefi to find out where the best forum was for getting answers to similar questions.

I was given many excellent suggestions, among them Practical Machinist. Register, and you'll have access to many experienced professionals.
posted by VikingSword at 7:59 PM on November 18, 2011 [2 favorites]

The object could be best created in folded sheet metal, in machined metal, in cast metal, as a welded assembly. Any of these might create "a small brushed aluminum object". The details, budget and artistic vision govern what is reasonable to make. Since machining and sheet metal have been considered, let me encourage you about the casting. "Lost foam" casting (where a mold is made by packing refractory material around a foam model, then heating until the foam is burned out) is practical - Saturn (car) cylinder heads were made by this process. If you wanted to make a lost foam, lost wax or similar part you'd provide the foundry with the pattern and ask them to cast it; or you'd provide the drawing/model to the foundry and ask for an "investment casting" or "rubber plastic mold" (RPM) casting if you wanted to make multiple copies.

Regardless you could be talking about an aluminum object that weighs up to 170 lbs (75 kg) or so. A cubic foot of aluminum would weigh 172 lb and the cost of the metal is significant.
posted by jet_silver at 8:20 PM on November 18, 2011 [1 favorite]

A company that manufactures store fixtures should be able to do it for you, such as this one.
posted by Ostara at 8:21 PM on November 18, 2011

As suggested above, you need to establish whether this is machined from a single chunk of metal, cut and folded from a sheet of metal, or cast in a mold out of molten metal. If we could get a look at a quick sketch, it would probably be easy to establish which is appropriate.

This could be a rather expensive thing to do. A rough cast or machined part would be fairly expensive to begin with (welded or folded from sheet metal less so), and then have to be rather painstakingly smoothed and polished to facilitate the final brushed finish.
posted by jon1270 at 10:01 PM on November 18, 2011

Ponoko has aluminum - not sure if your dimensions will work with their constraints, but it's worth investigating.
posted by judith at 11:11 AM on November 19, 2011

how many? what functional purpose? cost limitations? schedule? why aluminum? how detailed? any reluctance to DIY?

without any details, it's hard to recommend an approach.

there are low temperature metal alloys that will melt at a lower temp than water boils, and these can be cast in rubber molds you can make yourself from clay, latex, or plaster. pretty easy and amazingly accurate.

depending on the specifics, there are many approaches. get a little more specific and you'll get better recommendations.

do you have a sketch? is this something you want to be kept secret?
posted by FauxScot at 8:27 PM on November 19, 2011

I'd like basically a "U" shaped piece of aluminum that's 1/8" - 1/4" thick. I would like to use it as a shelf as a part of a modern-themed room. Something similar to this but thinner, with curves instead of straight edges, and in aluminum. Perhaps this is already sold somewhere, but I thought what the heck... nice DIY project/learning experience.
posted by uncannyslacks at 1:22 PM on November 23, 2011

Your original question sounds like you want to make a bunch of them for sale; the followup sounds like you want a couple for personal use.

If it's the latter, and I wanted something like that here in Minneapolis, I'd start at Discount Steel. Years ago I had them make a stainless steel backsplash for my kitchen. I just walked in as some guy who didn't know anything except that I wanted a wall covered with steel and they told me just what they needed as far as measurements and drawings. It wasn't complicated; they didn't need finished CAD drawings or anything.

For your thing, it looks like they sell the stock and provide the forming service.

Maybe there's an outfit like that near you.
posted by chazlarson at 2:39 PM on November 23, 2011 [1 favorite]

That is most easily made in sheet metal. It would be easy to make in 1/8" stock, more difficult but still do-able in 1/4" stock which would look a hell of a lot better with chamfers - not rounds - on the edges. You will have to pick the alloy carefully - the standard 6061-T6 will crack unless you specify very generous radii. Think about using 5052-T4, whose bend radii can be tighter without cracking the material. If you use 1/4" stock, and you consult your sheet metal shop about bend allowances, you will probably fare pretty well with that.

Sheet metal shops are accustomed to applying "graining", which is the brushed effect you were asking about. Beware, the grained aluminum is very difficult to dust. You may want to consider a coat of lacquer over the finished piece.
posted by jet_silver at 7:23 PM on November 23, 2011