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View Full Version : Forget CNC - check this out . . .


Bama Steve
February 17, 2009, 20:45
Computer based parts duplicator - let your mind work on this for a bit . . .

http://www.jaylenosgarage.com/video/video_player.shtml?vid=944641

phillip
February 17, 2009, 21:21
My Dentist, The Butcher, Used something like that to make me a bridge.

yovinny
February 17, 2009, 22:11
I dont get all the excitment :confused:

It makes a plastic reproduction, not a real part, nor does it interface with a maching center to make a real part.

They talk about making a model for casting a real part, but dont say is it's capable of adding for expansion, draft or anything thats required for a real part mold.

What exactly do you do with it ?

brownknees
February 17, 2009, 22:44
For some reason the video won't load for me. I'm just guessing here as to what exactly the gizmo is doing.
I know of 2 systems for model making from laser scanned originals.
One uses a UV setting liquid polymer.
The original is laser scanned, like a CAT scan for people, that's the common ground for the two systems.
The first one uses a focussed UV light shone into a tank of the uv set polymer, as the beam "hits" an X,Y,Z coordinate the polymer liquid is hardened.
After the whole run is complete there is a hard plastic replicant of the original, plus the CAD/CAM data on the hard drive. The polymer model is used to error-check the CAD/CAM programming & make changes as needed.

The other uses sheets of paper, stacked vertically, like a box of printer paper laying on a store shelf.
The laser scan in this case is set for "passes" where the original is scanned into thin slices, each matching the thickness of the paper stack.

Once the run is complete the combination of a laser cutter & a paper handling machine cut each sheet of paper to match a "slice" of the original. The cut sheets are peeled away, moved to a "re-assembly" module & restacked with adhesives applied. As the sheets "stack" they make a kind of super slim contour 3-D model of the original.
Again ther is a CAD/CAM program written annd the replicate model is used to check, or modify the CAD/CAM instructions.

Hopefully somewher in the models there is a "start" reference, somehow matched to an X,Y,X, coordinate in the "model"

Bama Steve
February 17, 2009, 23:20
Originally posted by yovinny
I dont get all the excitment :confused:

It makes a plastic reproduction, not a real part, nor does it interface with a maching center to make a real part.

They talk about making a model for casting a real part, but dont say is it's capable of adding for expansion, draft or anything thats required for a real part mold.

What exactly do you do with it ?

How far away is the technology from where you want it to be?
I'd say not far at all. A few more years and you'll be able to drop a hunk of metal in the "printer" and out will come a machined part.

Bama Steve
February 17, 2009, 23:22
Originally posted by phillip
My Dentist, The Butcher, Used something like that to make me a bridge.

Ask the "Butcher" to build you an AR lower . . . . He'll need one for himself if he is "up on things" . . .

ggiilliiee
February 18, 2009, 12:41
old stuff ...saw one in an oregon machine tool expo ....six clicks out of vancouver "96"...proto type maker ....still having dimensional problems due to the polymers ....

Clownshoes
February 18, 2009, 13:21
3D printing/rapid prototyping has been around for awhile and comes in many forms. I've even seen one that uses powdered steel that gets fused together by a laser to build up the parts.

The parts themselves are mostly used for show and tell stuff and preliminary fit and function tests. There are companies who are able to make parts that are strong enough to be used in real applications but the prices tend to be comparable with actual machined parts.

The 3D scanner is very cool, from what Jay was saying it sounded like the scans could be converted to solid models and loaded into the CNC machine to make real parts...the ABS part was just to see if it would work. I was surprised how small it was, I've seen a 3D scanner before and it was much bigger than that.

I can see tolerances being a problem though, it's like making a copy of a copy.

Anyway, I would love to have any of that equipment in my garage. I've worked with one of the dimension machines before at a previous job...the "soluble" structure they talk about doesn't magically dissolve away as easily as they they make it sound usually requires a good deal of picking with dental tools to get them all cleaned up. That one assembly they showed of the steam piston probably took more than a day to run also, they made it sound like the things are done in a matter of minutes. I've also worked with a machine that uses UV epoxy instead of ABS, it drops a layer that is followed by a UV light to cure it, that machine was cool and the substructure on those parts you just blew off with a small water jet, it was much cleaner.

Indycar
February 18, 2009, 21:39
The scans can be turned into Cad files and most good CNC machines can write or convert it into a program off a CAD file.

mountainman
February 18, 2009, 22:02
From what I remember, the resin costs about $700 a gallon.

Bama Steve
February 19, 2009, 01:06
Group buy?

:biggrin:

evan price
February 19, 2009, 02:46
Saw something like this when I was doing a job at the NASA research center. They were producing turbine blades using the thin sheets of plastic method. Kinda neat. Not much of a difference from that and using thin sheets of metal that get fused in an oven, like a sintering process, I'd imagine. Not great for high stress high strength applications but A-OK for an AR lower I would imagine, esp. if Cav Arms can do them in Nylon-66 at least...

As long as the engineer figures the calcs right, this could be done to make a mold in a lost-wax type of casting process, using a low-melt-temp polymer as the prototype material, then ceramic-dip coating it to build up a thickness, kiln firing, then using that to pour your part.

mountainman
February 19, 2009, 14:51
I think you have yourself a good candidate there. AR lower really isn't a stressed part.

LtRiker
February 22, 2009, 19:15
I saw this at a SHOT show years ago, Remington was working with it to try to speed up production...not sure where they went with it.
In the factory I visited, they were making 870 receivers three at a time at about 15 minutes per run for a complete ready to assemble part.

Temp
February 23, 2009, 02:07
They recently purchased one of those machines where I work.

Included with it were some demonstration programs to show it's abilities.Everything it makes is a plastic mock up, but it's pretty amazing.

It lays the part up in extremely thin layers.

One of the demonstration programs was a circular loop of bicycle chain which is exactly like the real thing..

The machine layed up a series of links and pins which actually function.

W.E.G.
February 23, 2009, 02:22
Alright!

There is hope for replacing that sprocket assembly on the old '73 vacu-jak after all!

Bama Steve
February 23, 2009, 02:47
I'm not sure I want to ask about that one . . .

Hellion Productions
February 28, 2009, 20:17
I've been doing stuff like this for years, usually in prototyping game and model kits. It's nice seeing it make the mainstream. I'm actually going about it backwards from most...started in RP, and now I'm learning CNC.

Objets are nice machines, curing photopolymers with UV light. 16 micron thickness layers. That's a nice resolution build. Their output wouldn't stand up to use, though, unless you wanted a translucent AR lower that wouldn't last an entire magazine. Even a .22LR upper would probably egg out trigger pin holes.

Objet's website is http://www.objet.com

Now, though, I know of at least one company that is making metal rapid prototypes.

http://www.exone.com/eng/technology/x1-prometal/

Best,
John Bear Ross