Rapid Prototyping/Laser Sintering

[Joe Pelonio]

Someone may have one of these or know more about them, but it sure is something I'd love to have in the shop. Apparently these will lay out a film of plastic on one pass, then adhesive on the next until it "builds" plastic prototypes. Really cool.

http://www.3trpd.co.uk/plant-list.htm

Videos about it:

http://www.3trpd.co.uk/gallery/video/index.htm

[Scott Shepherd]

Couldn't quite understand it from the clip I watched, but I do recall seeing Stereolithography years ago. It took a vat of liquid resin and burned it into solid in layers. It would burn a layer, then move the table down and burn the next. It was very cool. You could take items from solid model software to prototype in about a day. I do recall it taking about 12 hours or so to complete a model.

Have a look for stereolithography when you get time.

It was very expensive then, but i'd assume 10 or more years have passed and the prices are probably down considerably.

[Mike Null]

We had one of those machines (stereo lithography) at one of our plants. Nearly 15 years ago it was almost a million dollars but we were able to prototype virtually anything smaller than a gallon of paint. At that price it was a real bargain compared to what we spent for out-sourced models.

[Brian Robison]

It's still quite expensive.
There are 3 types that I know of. One uses a laser to sinter the metal and form a 3D part and another uses plastic in layers (both described). A third type cuts layers of paper to form a 3D part.
I saw the laser in Chicago a few years back. Very interesting. You can make inserts for molds this way.

[Joe Pelonio]

We had one of those machines (stereo lithography) at one of our plants. Nearly 15 years ago it was almost a million dollars but we were able to prototype virtually anything smaller than a gallon of paint. At that price it was a real bargain compared to what we spent for out-sourced models.
Ouch! That's more than my budget. I found lots of manufacturers but no published prices.

[Dave Jones]

Prices on stereolithography machines dropped a lot a couple of years ago (I believe when a couple of the original patents expired). I've seen small systems as low as $10k-$20k, and larger systems for twice that. There are still the $100k+ systems, but the lower cost systems are getting fairly common.

[Peter Zacarelli]

Z Corp has similar printer starting from 20K that make color 3D models as explained below. They seem really cool :D, if anyone wants their site address then email me.


Z Corp. 3D Printers set the standard for fast, affordable, color 3D printing. The printers create real physical models direction from CAD and other digital data. The prototypes can be used for design review, mock-ups for form and fit testing and patterns for casting applications.

Z Corp. 3D Printers use a powder-binder technology invented at and patented by the Massachusetts Institute of Technology to create parts directly from digital data. First, the 3D Printer spreads a thin layer of powder. Second, an ink-jet print head prints a binder in the cross-section of the part being created. Next, the build piston drops down, making room for the next layer, and the process is repeated. Once the part is finished, it is surrounded and supported by loose powder, which is then shaken loose from the finished part.

[Jim Good]

Right now I am in Detroit at the RAPID 2007 conference where all the rapid prototyping systems are on display. I had to present the work I've been doing for NASA/Marshall Space Flight Center. We are developing a system that will be placed on the moon surface and ultimately on Mars which will fabricate metal parts, as needed.

I helped purchase an Electron Beam Melting (EBM) machine (built by Arcam AB, Sweden) that uses an electron beam to melt successive layers of metal powder. We typically use titanium but you can also use stainless steels, inconels, and aluminums. A 3-D CAD model is sliced into thousands of layers and the EBM machine will melt a layer and the plate will lower one layer and then the rake will apply a new layer of powder on top of the previous layer.

Selective Laser Sintering (SLS) is simiilar to the EBM machine except it uses a laser instead of an electron beam. The SLS machine sinters the powder so it is not 100% dense but still makes a nice part if material pedigree isn't a concern.

Here's a link to check out Arcam's EBM machine. http://www.arcam.com/

Stereolithography (SLA) is still around and a significant number of materials have been developed lately. There is a fire-retardant material, a rubber-like material, and a polycarb material for strength among other materials. They run $100k and up for the better machine.

Fused Model Deposition (FDM) is a cool system, too. It takes a plastic wire and is feed through a heated extrusion nozzle. It applies the material like a cake frosting syringe. It builds parts layer-by-layer. Google "Stratasys" for more information. We have flown this machine on a KC-135 and subjected it to zero gravity and had it extrude material under this condition. It worked nicely!

Sorry for making this so long. I enjoy working with this technology. When we are on the moon making parts for the moon base, it'll be nice to know I had a little something to do with it.

Here is a cool desktop model for only $5K. http://www.desktopfactory.com/our_product/

Thanks for listening!

Jim