[HH] 3D printing vs. desktop CNC

[Greg London]

> Greg London wrote:
>> There are already plenty of existing CNC conversion kits out there
>
> But that's MakerBot kit territory, rather than a nicely packaged
> ready-to-use peripheral. You can't really compare costs. A purpose built
> device that is mass produced not only benefits from volume production,
> but also through having an optimized design.

Well, currently, production built CNC mills cost many-thousands of dollars
price range. Here's one that sells for around $6k.

The spool-based 3D printers sell in the $1k to $2k range.


> For example, the typical milling machine used as a basis for a D-I-Y CNC
> is a general purpose device that is no doubt rugged enough to handle
> milling steel. A low-cost desktop CNC would compromise those
> requirements and limit material choice, just as current 3D printers are
> very limited in their material choice.

But why buy a subtractive CNC Mill that can only handle plastic
if you can get a printer that prints plastic for less money?
A printer can always out-print any mill because you can print
stuff that is impossible to mill.

The one and only advantage of CNC milling is material strength.
You can mill steel and at least right now, you can only print plastic.
If you're doing engine components or pieces for a pump or a hydraulic
cylinder or something that requires high strength steel, then
CNC mill wins out.

If you're doing something that doesn't need high material strength,
then just print it in plastic.


> Right, Bill raised that point, and Jack brought up laser cutting as a
> possible solution to both the noise and "print head" weight problem.

I thought he was joking. Last I knew (admitedly this was years ago),
lasers that could mill steel were insanely priced custom jobs.


> over subtractive technology. The end-game for additive technology is not
> squirting out melted plastic or metal powder, but assembling objects at
> the atomic or molecular level.

Well, hell, if we can print at the molecular level,
you're talking a technological singularity of the
likes we may never have seen before.

We can fab asics at nanometer levels, but the NRE is half a million
dollars. Just because we can DO it doesn't mean it will ever become
cheap enough for everyone to have one on their desk.