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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 are discussing the job of people who practice materials science. Materials scientists study a lot of chemistry and some physics and also learn a lot about shaping solids. Other areas of interest are molecular structures of certain materials and manipulating various structures tiny scales either chemically or mechanically to produce the indented material or structure.
Try finding a machinist or a materials science firm that does designs for and implements commercial plastic or metal housings for consumer products. These firms are few and far between, and most material scientists work directly for companies that mass produce products, but you should be able to find someone to help you. The best bet for you would be to come up with a detailed design for the housing and hire a firm to produce prototypes for you according to the design. The shaping of plastic and metals is not something you can really do in your home, unless you are a materials scientist or you have a great deal of knowledge and experience with such things.
Thanks,
Travis
forkspoon@hotmail.com
You could send your design as a cad file to Toybuilders and they'll 3d print you one.
However as you've already made your model you'll want it scanned. There are companies that will do this for you too - though they dont quote prices like Toybuilders do, so I guess it'll be expensive.
I noticed from Neco's page that a Rapid Prototyping and Manufacturing exhibition is taking place in Cincinatti on Tuesday (29th April) until May 2. If you get the list of exhibitors I am sure someone will be able to help.
Cheers,
Baz
well, if you're really going for a simple/lo-tek/ghetto solution, check out sculpey polymer modeling compound. It's easy to find, simple to work with, non-toxic, and once you bake it, you're all set. The only immediate draw-backs are the fact that you're going to have to pre-form at least a starting hole for any screw-mounts (unless you want to get fancy and use pre-tapped cores...) and your project may end up looking like a bad craft project. Then again, I have to suggest it for simple DIY factor and simplicity. Shape, trim, bake @ 250, done!.
But then again that's just my 2 cents and I already use it for some craft projects, so YMMV. I do have to agree that there are some nice 'professional' resources that are now available to hobbyists with the expansion of 3-D printing and virtualization for one-offs and short-run, but for ~$2 an ounce, you can't beat sculpey for a fast and dirty way to mock a case. A friend of mine did a replacement faceplate for his old Nokia and was offered $60 for it. go figure...
"If I wanted your input on my pet project, I'd stick my hand up your ass and use you like a sock-puppet." - Muse
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.
It depends on how crazy you want to get. If it's going to metal, try going down to your local machine shop and asking them, OR post a question on Rec.crafts.metalworking
Even if it needs to be cast, that can be done (esp if you want it done in Al) - you could look up "Backyard Foundry"
Of course, now we're talking about a REAL geek hobby - Metalworking! Hot metal, dangerious tools, and it takes a brain
-- 73 de KG2V For the Children - RKBA! "You are what you do when it counts" - the Masso
How about the same question but with limited production runs? How could you build say 20 to 100 plastic or metal (whatever is cheap) small electronic cases?
The small time inventor is back.
Rudy
1. 2.
Check out Lindsay books. Make sure you get a dead tree catalog, not all their books are online. They have books on how to do a lot of cool things that you can apply. Glass, sheet metal, poured metal, pottery, Plastic (injection or vacuum) molding. All on a dot it yourself from scraps. Most of their books are from the early 1900's, so they are obsolete compared to modern mythods, but still useful. Note that you would have to be crazy to do some of what they will tell you how to do. It would still be fun to do it though.
Yahoo has a group of Hobbicast If you are interested in metal casting (my personal interest). I'm sure there are other groups for those interested in other materials.
Have fun!
I purchased a few strips of mouldable plastic. I'll check into the brand information if I can find them. Basicly you heat up the plastic in water, or with a heat gun and it melts, you pour, or mould (depending on the consistancy you want) the plastic into the form you want.
note that carbon fibre parts are *expensive* and dangerous to work with even though they look nice. always wear a organic respirator and gloves to prevent carbon fibres entering your skin (which they do pretty easily) and the resin from overwhelming you with fumes.
molds can typically be made for 400 bucks and the part for another 500-600 bucks. fibreglast.com gives all the info including technical brochures anyway.
QuickParts will make a part for you out of various materials. You send them a 3D file (STL) and they send you the part. Pretty cool, really.
They have an online automatic quote generator for most rapid prototyping. It's a bit pricey, a small half-dollar size part I had quoted was around $150 (+/- $50 depening upon materials, size, complexity, etc..).
--Tim
It's not clear exactly what you are trying to do... Or why existing project containers would not suffice.
But you might find the techniques involved in building Star-Wars style stormtrooper armor useful... At the very least, it's an interesting read...
The reason that existing project containers would not suffice is because my project is an exercise in shape design as it applies to usability.
Basically, I'm trying to create a working prototype so I can test how usable it really is -- and a lot of that usability depends on the form factor of the device.