rapid prototyper for only $2.5k!

[Admin]

An open source site for making your own rapid prototyper at just $2500 has been released:

"Full documentation on how to build and operate the machine, along with all the software required, are available on the Fab@Home website, and all designs, documents and software have been released for free."

info:
http://www.newscientisttech.com/article/dn10922-desktop-fabricator-may-kickstart-home-revolution.html

the site can be found here:
http://www.fabathome.org/

I use ABS rapid prototyping all the time, saves me huge amounts of time making/modifying robot parts. But in my experience the quality of material means a lot. Even $50k machines have problems with material that cracks on me . . . I feel rapid prototyping with ABS is the best because although low in precision, the parts dont break on me when bent. Would be nice to have one at home . . .

[JonHylands]

Admin,

You said in your post you use these machines all the time. I'm working with an AI group at a university in NH who are building a small biped (from a Bioloid kit), and we're talking about getting a Dimension printer for making custom parts.

What kind of printer do you use?

How well does it work?

What kind of resolution does it produce?

If they get one, one of the things we want to produce is a gripper for the hand. I've designed a simple one using CAD, you can see a render here:

http://www.huv.com/gripper-04.JPG

Scale wise, that is 93 mm long, and the wide part is 20 mm wide. How well do you think something like that would print?

- Jon

[Admin]

The three major rapidprototyper companies out there are:
http://www.dimensionprinting.com/
http://www.3dsystems.com/
http://www.stratasys.com/

You should be able to find some of the info you need on their sites. If you dont see it, call and ask. The specs and prices I mention below probably change often with technology, so better that you verify than take my word on it.

So the ABS printer I use is the Eden250 from Stratasys ($59,900). It has an X/Y axis accuracy of +/- .001" and Z axis of +/-.005". As such, you must pay attention to which way the parts are built (vertical vs horizontal) to maximize accuracy. There are various tricks to how you design the parts to improve accuracy. The material is really strong, but the connection between layers is the weak part. The layers can be as thin as .01" and the maximum part size is 8"x8"x12". The layers are slightly rough, but sandpapering the part can make it really smooth. Im generally happy with this machine, but the process is kinda slow . . .

I tried using the 3Dsystems prototyper (InVision, $39,900) for my application, but the new material was too brittle for me. They discontinued their older much more flexible material type. I required parts that flexed, but theres just cracked. The 3Dsystems devices also cant handle thin parts, because there is a heating step to remove the support material - if you thermally cool it unevenly, the part bends with thermal stress. One of their machines does have the highest accuracy in the market, but the parts are extremely fragile . . . The interface and process is simple - would probably take you 20 min to figure it out on your own. But dont trust their 'snake-oil' salesmen, I could tell they would say anything just to sell their product
"Special price just for your organization" (I work for the gov't, so we know what that means . . .) "Your parts came out beautifully!" (my parts were warped when they gave them to me, and looked nothing like the CAD) etc etc . . . I think their printers are more for visual prototypes and much less for functional prototypes.

For all companies, you can ask them to make samples of parts (it costs them almost nothing to do that). They will even send reps down to talk with your group.

As for your gripper, the prototyper I use can easily make that, and the part will be durable and strong.

[JonHylands]

Thanks Admin,

I have already looked at all the specs and websites, and such, I was looking more for a user perspective. Based on the specs, I have already settled on the Dimension printer, which goes for $18,900. These parts we want must be functional, so ABS is the only way to go.

Anyways, you told me what I need to know. Thanks again...

- Jon

[JonHylands]

Here's another one:

http://reprap.org/bin/view/Main/WebHome

This one is more interesting, in that it has a heated head for printing plastic parts.

I had an idea while I was looking over this site:

Since the print head is a separate piece, you could mount in on a CNC Sherline mill and have a very accurate 3D printer for about $2500. Especially if you machined the print head using decent materials, instead of being worried about building one that can print itself.

- Jon

[Admin]

but how do you get the CNC to stay in sync with your injecting mechanism?

i have a HAAS Mill at work . . . i guess it requires some serious hacking . . .

[JonHylands]

Well, the print head has a motor drive as part of it, and thus it can dole out the material in a very exactling manner, controlled by the same computer that is controlling the stepper motors.

I think if I was going to build one of these, I would machine a more sophisticated material feed system - theirs is interesting, but too oriented towards the whole "machine make copies of itself" concept, which is cool, but not what I'm after.

Probably a small rubber driven wheel, with a second spring-tensioned wheel on the other side of the material, would do a better job of feeding.

- Jon

[Admin]

Two new 3D printers now available with significantly lower prices (but still way too high for most people).

Desktop Factory
$4,995
"The cost of the build material is expected to be about $1 per cubic inch." It appears to have low accuracy and requires the user to paint the part to give it a nice smooth finish.
http://www.desktopfactory.com/



V-Flash? Desktop Modeler (Made by 3Dsystems)
I cant seem to find any specs on it . . .
$9,900
http://www.modelin3d.com/

[Ro-Bot-X]

$2.5k??? Maybe for $250!!! Check this out: Darwin, the RepRap v1.0...

I want one badly!!!