Metal Fabrication

July 12, 2009 4:04 PM

Metal Fabrication: I'd like to design small objects and see them realized in stainless steel and/or aluminum. How would I go about this? Specifically: What design software should I use and what services are available for custom fabrication?

By small objects, I'm thinking of everything from small tools and pens (two pieces that screw together) to simple geometric shapes.

posted by aladfar to technology (7 comments total)

This depends on how many pieces you're looking to get made for each small object/assembly.
For one-off custom fabrication, you're usually better off supplying 2-D technical drawings to a skilled, independent machinist who specializes in prototyping. These drawings can be done by hand if they use proper drafting notation on them.

Shops that use solid modeling and computer-controlled machining are better suited to medium to large runs, as there is the overhead of programming the machinery, but once that is done, the per unit cost goes down quickly. The basic solid model file format is .IGS, though most shops will support all the common ones on the market; a good shop would also want to see a 2-D drawing that defines materials, tolerances and finishes. Again, software recommendations will depend on the scale you intend to operate on.

In my experience, CAD software with useful solid modeling capability will cost you at least $1000 (legally), if not more.

Shops will be able to do a lot of different things, either in-house or by subcontracting. Off the top of my head, the main areas shops specialize in will include machining (milling, turning, drilling, reaming, tapping, etc.), welding, surface-treating (anodizing, alodining, painting, plating, etc.), and sheet-metal work (bending and cutting sheet-metal)
posted by cardboard at 4:30 PM on July 12

emachineshop.com is one place to visit. they provide the CAD, the quote and the piece.

Not particularly cheap, but kind of what you are looking for.

Another alternative is a replicator. There are some actual commercial items out there if you look. Kind of a 3d printer for prototypes.

Email if you want more info.
posted by FauxScot at 5:08 PM on July 12

Doesn't emachineshop offer services like this?
posted by glider at 5:15 PM on July 12

ponoko is an awesome service that will do laser cutting for non-3d types of things, and shapeways will do '3d printing' models (not in metal, but good for prototypes).
posted by logic vs love at 7:15 PM on July 12

Make sure your print has at least three views from different perspective, every dimension listed and tolerances given. This include radii, angles and everything else. Folks in this business do not like casuals because of the amount of extra time it takes to nail down the un-described features and the inevitable sticker shock, ($50 an hour or so) so take your time and draw and callout everything. A machinist does not like to make judgment calls and try to guess what you really meant.
posted by Iron Rat at 9:47 PM on July 12

Bathsheba Grossman creates complicated, often math-inspired sculptures using 3D metal printing. Here's a description of her process, including a link to the fabrication service. So that's one way to do it.
posted by fermion at 1:16 AM on July 13

What design software should I use and what services are available for custom fabrication?

Two popular bits of software are SolidWorks and AutoCAD. Prices vary substantially, but a single non-educational copy usually costs in the region of $4,000. You could look at the recently-announced SolidWorks Engineering Stimulus Package, which might get you a free copy (not for commercial use).

On the other hand, emachineshop has software you can download - and you probably don't need or want the complexity of serious high-end cad software.

By small objects, I'm thinking of everything from small tools and pens (two pieces that screw together) to simple geometric shapes.

I spoke to some of the machinists who produce prototypes for me. I asked if they could make a metal pen in two parts, to screw together in the middle. They reported that to make that would be "a right ball-ache".

On the other hand if you wanted something like a hammer head or a solid metal pyramid that would be easy to make on a 6-axis milling machine, but it would cost a lot more than just buying a hammer in the shops.
posted by Mike1024 at 6:16 AM on July 13