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Old July 5th 17, 07:16 AM posted to sci.space.policy,sci.physics
Fred J. McCall[_3_]
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Posts: 10,018
Default Towards the *fully* 3D-printed electric cars.

JF Mezei wrote:

On 2017-07-04 14:19, wrote:

Metal powder deposition and laser or electron beam sintering.

BTW, metal powders tend to be explosive.


Thanks. Does this really produce parts that are on par with those
produced with conventional means when it comes to
force/strength/endurance (especially when it comes to re-usable engines) ?

It appears so as SpaceX uses it, but just wondering if the physics of
melting layers of powder yields the same strength a a solid block that
is machine tooled.


"Compared with a traditionally cast part, a printed valve body has
superior strength, ductility, and fracture resistance, with a lower
variability in materials properties. The MOV body was printed in less
than two days, compared with a typical castings cycle measured in
months."

http://www.spacex.com/news/2014/07/3...chamber-crewed

So with regard to Chimp's claim of 'slower' and your concern about
'weaker', SpaceX says bull****.


Also, if it is powder, how do they make a "roof" over empty spaces (such
a the top of a horizontal cylendrical pipe inside the unit).


Silly question. How do you make an igloo? Same thing but with much
tinier blocks.


--
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