Darren,
Smári offers some great tips here especially from the "what techniques
can I use to get a first functional prototype?" perspective. I'd like to
address your questions on DFM (design for manufacturing) and production
from the perspective of a working engineer.
>> If I've had an idea for a product, how can I go about mass-producing
>> it in order to sell?
Smári more or less covered this - I will point out that making a
functional prototype can be very different from making a mass-producible
design (example: I can make a motor controller in <1hr from "I have an
idea!" to "I've breadboarded a circuit and have a motor spinning on my
table," but laying out the PCB, making sure the case design I have in
mind is injection moldable, etc. would take days or weeks more to verify
(ship it out to manufacturers, argue with them about tolerances, pick
materials, get it back, complain about the solder masking, repeat...)
>> For instance, a small gps transceiver in a simple plastic or rubber
>> casing.
That's still a pretty generic statement. What does the GPS device do?
What chip will it use? What requirements (does it have to be durable?
small? light? waterproof?) does it have? (All these will dramatically
affect cost; I'm talking a 2x-10x or more difference and that's a rough
guess, even.) Plastic or rubber - what type? The exact material will
determine what fab methods you can mass-produce with, which will
drastically affect the cost. Also, what quantities? As Smári pointed
out, setup cost is usually the bulk of what it takes to produce a first
round of mass-manufactured prototypes.
>> - can I find out how much this would cost to produce? (and can i find
>> out for free?)
If you have a detailed mass-production design, yes. You can send that to
the companies that would mass-produce it for you and get a quote. If you
have a working prototype, you can usually work with an engineering firm
or an engineer to give you a rough quote on how much it would cost (1)
them to redesign it for mass-production, and (2) mass-produce it. (The
first is often dependent on the second; it will take me more time to
reengineer something to make 10,000 $10 prototypes than it will take me
to figure out how to make 100 $1000 prototypes, and there are boundaries
to how cheaply I can make something at all - for instance, a laptop for
$5 isn't going to happen soon.)
Given the description above ("small gps tranceiver in a simple plastic
or rubber casing") you're going to get one of 2 answers:
(1) Exactly $X. (Run away. Run away VERY fast. They can't possibly know
this. It's like saying "How much will my birthday party cost?" and
someone saying "$125" without asking you first whether you'll be sharing
a single bottle of cheap wine with 3 friends, or flying in performing
elephants for a 2,000 person gala.)
(2) It Depends. (or "It depends, maybe between $X and $10X or so, what
are you trying to do?")
Good engineering firms won't work with you unless you have a solid plan
and resources to back it up - a working prototype and the knowledge of
how you're going to finance it, take it to market, etc. Their work will
also almost certainly not be free (example: as a lowly intern at the
product design consultancy I worked for, customers were billed $75/hr
for my work, and this was when I was 19 years old, a student, etc - so
think about how much an experienced engineer costs. Think order of
magnitude.)
A good firm will, however, talk with you (if they think you are serious,
not just a person with a cool idea who has no idea what they are getting
into and might flake out when they realize how difficult it is - because
it can be *really* hard to get something to market) to explore the
possibility of a relationship, and you'd work out these kinds of details
during those conversations before you talk about how much you'd pay the
firm. Some firms - not all, but some - will do pro bono / reduced rate
work for things that they *firmly* believe in, if they see somebody
standing there who can and will take it "all the way" except for this
One Part that they don't have the resources for ("if only I could
redesign my mold to use this eco-friendly plastic.")
This is probably more than you wanted to know - and not to scare you
away from doing things, it *can* be easy - you can make something, fab
it at home or in a friendly local shop, maybe it's a design that people
can do themselves ("hey, get a milk jug and some scissors, cut like
so...") but it can also be a difficult, long, and complicated process
and some people don't expect that and that hangs them up.
My philosophy is that if you acknowledge that the worst-case big
expensive blown-out thing *could* happen and learn about that, and
*then* go "Ok - how do we get this done without expending all those
resources and time?" you end up with fantastic results with clever
shortcuts that don't degrade your process or your product, and you're
not continuously having heart attacks because you just learned how many
thousands of dollars it would cost to make a mold.
I am a hacker. I make things in my living room, in friends' warehouses,
garages, everywhere; I love the cheap, last-minute, quick-and-dirty late
night hack. I'm also an engineer, and I know how far hacks tend to go
(and not to go), and if you want to make a big impact and change the
system later, the easiest and fastest way to do it, imo, is by going
through the current systems, learning about them, fixing them as you go.
What I described above is the current system. We learn from it, we make
our own, we change it from the inside.
-Mel
