SpaceBanter.com - View Single Post - Towards the *fully* 3D-printed electric cars.

**David Mitchell[_3_]**

wrote:
In sci.physics David Mitchell wrote:
wrote:
In sci.physics David Mitchell wrote:
wrote:

Does anyone care about a shape optimized 4 slice toaster or filing cabinet?

Yes. I do.

If any significant number of items in your house are fabricated, it makes sense
to use as few raw materials as possible, so, for example, it would make sense to
honeycomb the inside of a knife handle, since it would still be strong enough,
and would allow you to keep a gram or two of material "in the pot" for other
projects.

Ditto everything you make.

Nonsense; the items in one's house are based on price not how elegantly
it was produced.

It makes no sense to honeycomb the inside of a knife handle as it would
add no functionality and just increase the price.

What price?

The manufacturing cost which increases the retail sales price at the store.

It would reduce both the time to fabricate and feedstock used, albeit at the
cost of slightly more complex software.

Or you could injection mold it, as most knife handles are, for a fraction
of the manufacturing cost of the honyecomb nonsense.

What do you think the manufacturing cost of fabrication is?
- Feedstock, most of which is, and can be, recycled,
- Power, minimal,
- Cost of the unit, divided by its expected lifetime, multiplied by time to print?

These are all very small.

Or you could stamp the whole thing out of metal for a fraction of the cost
of the honyecomb nonsense.

They form the only metric which makes sense when talking about fabricating objects.

The only metric which makes sense for fabricating objects is the loaded
manufacturing cost.

So, by that metric, they're cheaper.

If an injection molded handle costs a fraction of a cent while the honeycomb
handle costs several cents, which is cheaper?

You've added a whole retail phase; which isn't really the point of 3-D printing.
I'm looking at a mature fabrication economy - when you don't buy most things
you fabricate them.

In that scenario, the economic case for large scale mass-production disappears,
because everyone fabricates what they want, or buys it from someone who does
(which would obviously be more expensive; but worth it, for example, if they
have a larger fabricator than you).