This article in Design News lists several “quick-turn” manufacturers. These four all offer injection molding: eMachineShop, Protomold, QuickParts, and ToolRoom Express. It still looks like eMachineShop has the easiest setup, with their custom CAD software and human-free quote system, but they seem to focus more on metalwork, so perhaps one of these other services will offer faster/better/cheaper results for plastic.
One of the things I’ve found useful with plastic is that because you can get as-strong-as-the-original welds using the right solvents building your one-off parts with weldments is often a reasonable way to build the basic shape.
And then, unlike when you’re working with, say, steel, because plastic is so easy to machine (just make sure you’ve got some powerful vacuum or blower on your tool to keep the chips from rubbing against each other, overheating and gooing up on your cutter) you can do the fine details as a machining operation.
So while in metal it’s worth your while to start many metal projects by building molds and firing some air into charcoal to melt for castings, with plastic, especially the sorts of things you want to injection mold but can’t afford to for one-offs or low volume runs, it’s totally reasonable to break out the router, cut the components, solvent-weld the thing into place, and then do final machining to get it just right.
The other thing you might look at are the various 3d printing mechanisms, depending on what you’re making.
Comment by Dan Lyke — February 26, 2007 @ 10:28 am
The parts I want to make are cases for wearable electronic devices – basically glorified project boxes. I’ve been making prototypes out of tupperware, pipe fittings, and other scroungery, held together with screws and epoxy, and now I’m thinking about production. These are going to be low-volume specialty items – fancy toys for burners and ravers – so unit price is less important than keeping the up-front investment cost low and impact on my free time to a minimum.
The exciting thing about eMachineShop is that it looks like a path from “making cool gadgets on my kitchen table” to “selling cool gadgets through a web store” that doesn’t detour through “borrowing lots of money, renting an expensive shop space, buying lots of expensive tools, and burning all my free time trying to make a business sustain itself”.
Comment by mars — February 26, 2007 @ 4:38 pm