3D models for printing on 3D printers,
sell for about $3 dollars.

With the a neat looking Cat Armor on Pinshape,
which is priced at $12.

I think what makes a good 3D model, printed or not,
is a beautiful and unique design.

And that it does not exist in stores,
due to its uniqueness - and even if it did, it would be too expensive.

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A person that buys a 3D printer for just about $200,
can print out an infinite number of knickknacks and curiosities.

The stores I see online are not quite there yet,
people don't seem to advertise 3D models as proper products with a standalone website.

To get a good idea what 3D products look like,
vist Thingverse, Cults3D, Youmagine, and Pinshape.

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Now from a more personal perspective,
I recently started learning Blender, a 3D modeling program.

YouTube is full of Blender tutorials,
I was pretty fun to learn the basics.

Blender is shipped with a 3D Print plugin that will evaluate geometry of a product,
and that truly lowers the on ramp, as one can click Check All, to catch problems at every operation.

Blender allows for operations that 3D printers are not always happy about,
the 3D Print plugin is a very pleasant way to learn what one can and cannot do.

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I have created a strange wallet as part of my self education,
And made a series of interesting discoveries.

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The filament that printers use as "ink" costs $30 dollars for a roll,
and lasts for a couple of months - it is best to start with the most popular white filament as white easily hides imperfections.

A print such as my strange wallet,
would take about 4 or 5 hours to print.

Before a 3D Model (often an stl file) can be printed,
it must be sliced by a Slicer, the .stl file is converted to a .gcode file that printers understand.

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You can't give something legs unless you want to print supports,
for example when building a simple wallet, one side should be flat.

You can't put a latch on the bottom, as the printers don't like complex shapes on the bottom.
though when slicing a model, one has an option to generate supports - awesome for fancy complex sculptures - but not so good for flat wallets.

Best product designs are simple, or at least come in multiple parts that are simple,
if you wan to have a lion head on your wallet, you should print that as a separate piece.

This way the back of the lion is flat, the back of the wallet is flat,
and you just need some superglue.

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The reason I designed my wallet as a case with hinges,
is because my next lesson is in designing a tiny computer case for the little Raspberry PI.

There is one big change I will make,
and that is to round all the edges, as they come out sharp - it is fantastic how tough that plastic is.

I made most of my wallet designs two millimeters thin,
to print them out very quickly, some of my designs took only an hour to print.

This latest design, has 3 milometer side walls on the main case,
it is perfectly tough - all the final designs that require toughness should have 3mm sidewalls.

A portable little computer case is a perfect 3mm sidewall candidate,
the case will not bend.

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3D Prints can have some minor warping,
and while temperature control can fix that, it is a good idea to plan for it.

The earlier design had a top without any side walls,
plus I was testing experimental hinges which multiplied misalignment.

This new top design, has overhanging edges,
and if there is any warping to the plastic, the top will still align perfectly, and the minor warping will actually contribute to keep the wallet closed.

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Modeling for a 3D printer,
is proper Industrial Design, whether an experienced designer of hobbyist, it is the same kind of fun.

My earlier design though sturdy enough,
had a card sized hole when improperly closed.

I didn't have a side wall up-front to easily slide cards out, when open,
but that also meant it had a credit card sized hole for the credit card to fall out if improperly closed.

My latest design has only has a hole for thumb and index finger on each side,
I restored the front wall that would allow cards to fall out.

It only took a few moments, but it was a wonderful feeling,
expanding my own creation, to account for new features and concerns.

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Making my little wallet-case taught me absolutely everything I need to know,
to make my little computer case.

More than that, I think I will be one of very few people,
who will build a Raspberry Pi case with with hinges where one can open it for easy access to the GPIO connectors, or even the SDcard.

My hinged Raspberry PI case with proper manifold geometry,
will be my first - dollar or two - product that I will sell in an online digital goods store.

I plan on having multiple case variations,
something that would be cumbersome for a 3D printed product as one would be printing parts that the customer would not have use for.

As a digital product, I can include cases that support batteries or various sizes,
or allow for securely mounting the case on top of a large power-bank.

I can even cover multiple recent variations of the Raspberry Pi models,
while featuring universal addons that snap onto all the different cases.

One can easily imagine how someone would prefer to buy a kit and a printer,
rather than continue buying new cases as they expand their inexpensive Pi collection.

One of the cases I hope to design is a Raspberry Pi Camera Case,
which is less of a case and more of a camera, really.

Finally, I would like to add that selling digital models,
does not mean that customers must own a 3D printer, as they can choose to have their digital models printed during checkout.

I will explore that configuration,
when I begin designing small sculptures and jewelry pieces.

The world sure has changed a little bit, video tutorials hold knowledge that previously required tutoring,
and one can easily buy a printer that can slowly extrude the entire contents of a dollar store - wow.