I remember seeing a web page describing a process that deposited (sprayed?)
material (plastic?) to build up a CAD design so that in the end you have a
3-D prototype of your design.
Basically, a CNC machine that adds material, not takes it away.
Can someone point me to a web reference of this type of machine?
Thanks,
Dave
There are MANY different such machines, and they produce imperfect
parts with different characteristics.
Basic methods are--
SLA - stereolithography, where a laser polymerizes a liquid and
it emerges from a bath of liquid like the creature from the
black lagoon
FDM - fused deposition modelling- sort of an automated glue gun
lays down layers. Eg. Stratsys.
LOM - laminated object manufacturing- a roll of plastic is cut
with an automated knife to create layers of the end product
SLS - Selective laser sintering (of powder). This has been combined
with inkjet color printing to produce colorful 3-D object.
Metal powder is possible.
Google for "Rapid Prototyping" and you'll find more info, machines,
service bureaus etc.
Part finish and material bulk characteristics are rather inferior to
solid material in every sense (strength, porosity etc.) and it's
possible to make structures that are not machinable and not
injection moldable (eg. with complex internal voids etc.).
If you don't mind doing a bit of work afterward (polishing, drilling,
filing, painting etc) you can get a fairly good idea of what an
injection molded part will look like before spending the money for a
mold-- even demonstrate functional prototypes at trade shows etc.
Ideal for 'industrial engineers' interested in cool sculptured shapes
etc.
I'm currently using several different methods (through service
bureaus) to create small quantities of plastic and metal parts for
high tech applications. I do the modelling in Solidworks, output an
STL file, send it off, and parts arrive by courier in a bit.
--Ifyawanna roll your own there are several open-source stereolith
projects in the wild. Check out reprap.org for one and there's another over
at makezine.com
You often don't need to go through the finishing steps if all you want to
do is fit checks or ergonomic studies.
I've seen the FDM stuff done in wax, and thought it'd be great way to do
one-off metal parts if you could just use it as the wax for investment
casting.
Tim Wescott wrote, On 11/3/2009 3:45 PM:
It is already available. The model along with gates, sprue, and vents
are made using an SLS or a ThermoJet rapid prototyping machine.
Tim Wescott wrote, On 11/3/2009 3:45 PM:
It is already available. The model along with gates, sprue, and vents
are made using an SLS or a ThermoJet rapid prototyping machine.
At the other end of the spectrum from DIY home stereolithography,
formatting link
Space explorers have yet to get their hands on the replicator of "Star Trek" to
create anything they might require. But NASA has developed a technology that
could enable lunar colonists to carry out on-site manufacturing on the moon, or
allow future astronauts to create critical spare parts during the long trip to
Mars.
The method, called electron beam freeform fabrication (EBF3), uses an electron
beam to melt metals and build objects layer by layer. Such an approach already
promises to cut manufacturing costs for the aerospace industry, and could
pioneer development of new materials. It has also thrilled astronauts on the
International Space Station by dangling the possibility of designing new tools
or objects, researchers said.
I had enquired:
"In the case of your product, I raised the question about using
the generated model as a ram EDM form after vacuum metalizing or
possibly using a conductive/graphite loaded matrix material.
I can also see easy core production for plaster casting, either
directly for low volume/prototype or for the waxes for investment
casting, including quick calculation of the shrink factors by
scaling the cartoon.
I would love to have one for my shop. What do the machines start
at, and how much is a resin cartridge?
Anyone operating a service shop where you can email the cartoon
in DWG/IGES etc. and get a part back?
In part their response was:
i Again,
I heard back from Gerry, one of our application engineers. Our
current
customers can use any CAD software that will output a STL file.
Once in
STL form - the files can be attached to our software and printed
on our
machines.
As for service bureaus, there are plenty out there. I have sent
this
email to Kirby Quirk, our sales rep out in your area. He can
connect you
with a shop that has the ability to print your parts with our
printers.
Again, if there is anything you need, please do not hesitate to
give me
a call (978-495-5542) or shoot me out an email
snipped-for-privacy@objet.com
Thanks and I'll talk to you soon!
Rich
__________________________
Richard Wolff
Inside Sales Representative
Objet Geometries, Inc.
5 Fortune Drive
Billerica, Ma 01821
Phone: 978-495-5542
Fax: 866-676-1533
Email: snipped-for-privacy@objet.com
Visit us at:
formatting link
Their email is now a little dated [13 Nov 2008] so Mr. Wolff may
no longer be there.
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