Blistering Barnacles: 3d printing smackdown

So now I have TWO Barnacle lamps.

After reading my post on 3d printing a lamp on a Zcorp 450 out in ADSK land, Jesse Roitenberg from Stratasys was kind enough to print a version on a Dimension uPrint. So I wired it up with a Sylvania portable LED work light . . .

which is nice because it has a magnetic base that I can stick to stuff.

There is a lot to say in favor and against the uPrint and Zcorp 450 printing process. In the end, which process you choose really depends on what surface you are going for, what your facilities are, and how much time you have available.

Post Processing

uPrint
Out of the machine, the piece appears much more durable. I didn't finish this one myself but Jesse said:
"Once the model is taken out of the printer you just put it into an agitation bath with heated water and a solution and the supports dissolve away. I believe this model was in the tank for 2-4 hours. Then you remove the model and the supports are gone. A quick rinse and I shipped it off . . ."

Zcorp:

I'm still amazed that I managed to get this one finished without breaking it. After excavating the barnacle from the powder by delicately vacuuming around the edges, and blowing the remaining surface powder off the exterior, I started blowing out every individual cell. This quickly became boring, so I took it outside for a good blasting with the shop vac on reverse, which worked well (although my car looked like a mime). I don't have access to a larger dipping or spraying facility to cure the final product in what is essentially superglue (I also don't like the finish this gives, a bit too shiny for me), so I've been using a clear enamel Rustolem spray finish. I emptied an entire can on this piece, in about 3 or 4 coats. The result is a very smooth, durable matte finish that has held up great for almost 2 years hanging from my ceiling. However, it took over 2 weeks of off gassing before I left the light on for more than a few minutes.


Durability

uPrint

The object is quite sturdy, and comes to seriously pokey edges. My desk is littered with fairly fragile Zcorp prints that my colleges have learned to handle carefully after a few tragic drops and smashes. I toss around the Strata print with abandon, which freaks out those who associate it with the more delicate counterparts.

Zcorp:
Using the Rustoleum finish, the object is still pretty fragile. I make sure that people are on alert when they interact with the thing. Again, the company recommends using a superglue finish, which is VERY durable, but I find the application process really unpleasant and the finish too plasticy. After a few coats of spray finish, I am able to do things like drilling and sawing the objects.

Surface Finish

Dimension:

Closer inspection reveals a pretty rough surface appearance. The dimension's printing process is similar to coiling a pile of thread, with one thin continuous extrusion of plastic being coiled upon itself over and over. Back in grad school about a thousand years ago I spent some time with a similar machine. Both this newer model and the older have the same thready surface, and in sharper area you can see/feel protruding loops . From a distance this is not noticeable, but is a significant aspect of the tactile experience.

The other distinguishing characteristic of this print in this application is it's translucency. With back lighting , the dimension transmits significantly more light.

Zcorp:

The surface of this print is quite smooth. Not autobody smooth, but like a piece of well loved sidewalk chalk. Part of this is due to the brittle product that comes out of the machine, where very sharp edges simply don't survive. But this is also a result of using the spray finish, which just slightly melts the granular surface.

The 450 is essentially printing in a gypsum based material, and is translucent only at its most thin areas. The result is a much higher contrast lamp.

I'm posting the original stl file here, so if anyone else would like to give it a whirl, send me a copy. Laser sintered steel anyone?