Help with prototype

Hi guys,

I’m in the process of creating a prototype of a product. This is the first time I am doing anything like this - I have absolutely no experience with product design, so I’m looking for any advice on the type of material I should use.

A little bit of info about the product: it’s basically a box, 150x75x25mm. I want it to have a lid with a latch that can be locked with a lock and key (very amateur sketch is attached). The best real world example I can think of is one of those old school metal lunchboxes (but smaller, and around half the height).

I would like to know what type of material can be used. Ideally I would like to use a hard rubbery material, or a flexible plastic like the kind used in Croc shoes. Also, I would like the edges to be rounded.

I also want to put a handle on the top so you can easily carry it around. My biggest concern is that the hinge for the lid will not work with some materials. Any input would be much appreciated.

Please let me know if any additional information is required.

First thought for speed is cardboard.

Second would be polyethelene sheet PE, easy to cut and score with a knife.

Third, use an existing box, there are hundreds of thousands of boxes premade in nearly every material and size. Usually the quickest way to arrive at a solution is the best.

EVA foam is what Crocs shoes are made from, you can buy sheets of it.

Not to be rude, but I’ll just say it plainly. This design isn’t anything new, in any shape or form. I’d just find an existing unit that fits your specs exactly. It will be much much (much) cheaper than building a functioning prototype from scratch, guaranteed. That is kind of the idea of Industrial Design in the first place… the create products for people which are more affordable (and require less time) than if they were to develop and produce them themselves as one-offs. More or less anyway.

I would like to know what type of material can be used. Ideally I would like to use a hard rubbery material, or a flexible plastic like the kind used in Croc shoes.

How do you envision a “rubbery material, or a flexible plastic” to hold any kind of form that would allow it to be hinged or lockable?

No idea. As mentioned in my original post, I have absolutely no experience with product design. Although as I get older I’m getting more and more interested in the field.

Yeah I considered purchasing pre-made units, but I don’t know where to find then. I tried AliBaba, but I want to be able to physically assess the potential prototype. A box store with boxes made from all kinds of materials would be ideal!

Perfect! I had no idea you could buy sheets of EVA foam! Thanks :slight_smile:

So it looks like the next step is to find a pre-made box, or have one made in the right material (most likely EVA foam).

One more question: would it be possible to create a box out of EVA foam with a hinge and latch? Looking at how Crocs are put together, I think it’s a possibility (see attached).

Thanks again guys!

Probably nearby you. Yoga mats for soft density. Interlocking floor squares as pictures below for a more stiff density.

Cut with a sharp utility knife, glue together with contact cement. Cut halfway through for a hinge, EVA should flex for quite a while before breaking if you cut right.

I doubt EVA foam will “stand up” in a box form factor. The sides and the top will all cave in. It works fairly well on those Crocs is because it isn’t exactly EVA foam, it is nice and thick, and it also uses the shape of the arch.

Again, I don’t want to be a jerk. But this sounds like saying “I want to make a prototype that is exactly like a Bic pen”.

It will end up costing you hundreds, if not thousands. It will take up hours of your time. The first one or two prototypes won’t work. If you have money and time that are 100% expendable, it could absolutely be a fun process though.

Small, in fact tiny box, 6-10mm thick eva will hold the shape just fine. Five dollars worth of 10mm thick EVA tile from your local Walmart, some contact cement, a sharp knife and a ruler, and in an afternoon you will have some boxes to play with and think about your idea. Good luck with the explorations.

I think you should totally take this up as a challenge to build yourself! Wood is a great material to work with to get started because you can cut and shape it with some affordable and fairly safe power tools. I think you could build this project with just a power drill and a jigsaw. If you’re interested in 3D modeling at all, you could even try downloading Google Sketchup, it’s a relatively easy to use 3D modeling software and you can get up to speed pretty quickly by checking out of youtube tutorials. This is another way to prototype your idea before you start building.

What I like to do is to go shopping for material ideas and things like the handles and hardware at home improvement or hardware stores. You could also stop at a sporting goods store to look at rubber materials like you were thinking. You’ll get a ton of ideas just spending some time walking around and seeing what’s available. Instead of buying materials right away, take a picture of them in the store and later you can look at all your options.

Good luck, have fun, and don’t worry about getting it right the first time. Go into it knowing you’ll make it two or more times until you’re happy with the final result. It can be frustrating but it’s not a waste because you’re learning essential skills for the next build you do!