How to Turn Your Concept Into a Prototype?

Synced0 asks: "Like a lot of people who post/read on this site, I am a software developer. I have experience developing handheld applications and am quite knowledgeable about the hardware that are in various handheld devices , these days. I have been toying around with the idea of building a device that is based on a handheld platform. I have the basics for what I need such as what OS, and platform I will base it on (motherboard, CPU, storage, display panel, etc). The biggest question in my head is where do I go for the actual design of casing, and who I can get to do the final hardware design. I have never designed hardware before, but now that I have my platform and such, where do I go from here? I have some ideas on what the device should look like, but I have no skills of molding plastics. I have all the pieces working on the desk but am clueless how I progress from this stage.Is it very expensive for someone to take concept into a prototype?"

Comments

Here's a partial answer

[UncleFluffy]

These people can help with part of your problem: http://www.emachineshop.com/

It doesn't look insanely hard or expensive

[petard]

I was looking into something similar for a Soekris-based project recently. ProtoCase looks promising. I haven't actually placed my order, so I can't comment on quality just now. I did download their software and do a quick design to estimate costs. Looks like, for a typical soekris-sized project with a couple serial ports and a couple ethernet ports I'd be facing approx. $130/unit in very small quantities with about $70 in one-time setup fees.

These guys have also occasionally been recommended on soekris-tech, and also offer free software to help you design and submit projects to them.

Good luck!

Re:Some answers

[WhyCause]

One thing to note, here.

Before you submit your plans to a molding shop or machine shop. have someone who knows something look at them! Yes, it is easy to draw something and have it made, but someone who has gone through this process a couple of times will be able to spot common pitfalls that most new designers fall into, namely:

• Tolerances far too tight - nothing will move if you have everything too snug, and machine shops start doubling prices for every extra significant figure on those tolerances.
• Your parts may not actually be manufacturable - if a machinist or CNC machine can't get to a place to cut away material, you just plain can't make the part.
• You have more than one part to be made - one case is likely composed of multiple 'parts', at the very least a front and back half, and if you don't split them out, you'll get one solid chunk back, not the smooth open/close mechanism you expected.
• You might not be able to put everything together - Tab A might fit into Slot B in your head, but if the tolerances aren't correct, or if you just goofed, the real parts won't go together like you think.
• Your cool design might be buildable, but not manufacturable - rapid prototyping machines can easily make things that are otherwise unmakeable; everything looks great for real production until the machinist/molder laughs you out of his office.

...they commonly have this device that can create any solid plastic shape in 3D using lasers

mnmn is referring here to a rapid prototyping machine, which is a really slick option for early prototypes because of the rapid turn-around time. CNC machines might be a second option, since the parts they make will be durable and very solid (unlike a rapid prototyping machine's output). At my undergraduate institution, we had a rapid prototyping machine (one of the first in the nation at university, by the way), and they would sell time on the machine to individuals/companies who wanted to have things made (Remington Firearms was a steady customer, if I recall correctly). I would suggest asking around at the local Mechanical Engineering departments if I were you, since they are likely to be much less expensive than a professional firm, and much more forgiving of design errors. They will also have access to CNC machines that they may be willing to sell you time on, provided you buy the materials and have everything ready to go (CNC machines don't just take 3D model files, you have to specify cutting paths, depths, and cut orders).

All in all, I'd suggest going to a bar near the local university on a Friday afternoon and waiting for the Mechanical or Industrial Engineering graduate students (they won't be hanging out together) to show up. Start talking with them or buy a few rounds, and they'll have better specific information for you.

mechanical engineer here...

[Anonymous Coward]

There are three basic levels of plastic part volumes and costing outside the realm of machining from a block of plastic.

Rapid Prototypes: SLA, FDM, SLS, etc. Google those terms to see what they are. No tooling involved. Companies all over the place make them. I'd suggest FDM prototypes from quickparts.com or redeyerpm.com. Probably $25-150 per part. Several days for turnaround.

Rapid injection molding: niche filled by Protomold.com. Cheap tools (between $2k and $10k for most things), relatively cheap parts ($5-$15). 1-3 week delivery depending on price.

Real injection molding: Jillions of suppliers. Tools take 4 weeks or more. Don't count on less than $10,000 for a tool. Parts will be as cheap as they can get.

All three avenues need a 3D CAD model at some point. You can hire a consultant engineer for ~$100 an hour in some areas to model it up if you have decent sketches with some dimensions. How pretty you want it will determine how long it takes. Figure a few grand for something decent. You might be able to find software on the web to do it yourself if you don't have the money.

If you have a big pile of money, you can hire a company to design the parts, order the tools, and fabricate your whole product. Figure many tens of thousands of dollars for labor if you go that route.

This isn't a fab problem

[Animats]

Actually, at this point you need to build two things. One is a functional prototype that fits in some standard case. The other is a non-functional prototype that shows the desired look and feel of the product.

The functional prototype you put in some standard case. It will be bigger than the final product, but it will work. Get a good catalog of boxes (Mouser and Digi-Key have good selections.) You'll have to drill holes and grind things down, which you do with hand tools and maybe a Dremel tool.

The look and feel prototype you have designed by someone who understands industrial design. It may be a clay model. There are polymer clays that can be fired in an oven to make a hard object. The model is then painted, and perhaps glue-on stickers are applied, followed by a clear coat. There are other approaches; you can machine the mockup out of a block of Delrin, or build it up in a stereolithography machine. Or if you just want to have pretty pictures, you can design the case in some 3D system and generate renderings. But for handheld devices, a solid object is more useful.

Now you can get user opinons on the thing. You'll make some mods, and may do another version of either prototype. Marketing and funding efforts begin.

Once you have a basic design that seems to work, you're faced with designing the real thing. This is a packaging job, and you have to think about things like design for assembly, waterproofing, shock and vibration resistance, interconnects, and similar subjects. If you can get the whole thing on one PC board, do so. If you can't, you get into interconnects, always a big hassle. Try for one PC board with surface mount components and a clamshell case that holds it in place; that's straightforward to fabricate in quantity. If your idea is any good, by this point you have some funding. So you get this done by somebody who knows how.

Incidentally, having custom membrane keyboards or rubber keyboards like a cell phone made isn't that big a deal, and you can get much of your job done by a supplier in that business.