Wednesday, April 28, 2010

So, what is 3D printing?

We are all faced with the question “so, what do you do?” I often think that for most people that’s an easy question to answer. I’m a banker, or a fireman, or a teacher. No explanation required. But when I meet new people at my son’s afterschool sporting events or at a social party and I know I’ll be faced with that question, I start thinking about my answer. I usually start out by saying that the company I work for designs, manufactures and sell 3D printers. The typical response I get from that “OK – sure” as if they know exactly what 3D printing is. This response is usually followed up by a confused look that signals me to start explaining…

Imagine starting with a virtual 3D object, one that can be rotated on your computer screen like a video game character or a model car. Most people I talk to have seen the old Lee Iacocca commercial where he showed off the Chrysler Motors design center and how they design cars using 3D software (Catia I believe). Now, imagine taking that model and slicing a very thin layer off the bottom. Looking down on that layer you could print what you see on any home or office inkjet color printer. So, now imagine that you place a second piece of paper on top of the first and print the next layer from the model. Continue this process until you have sliced and printed each layer of the model all the way to the top. You now have a stack of paper the height of the virtual model. If everyplace that was printed on within and between layers became bound together and everything that was not printed on just fell apart, you would have a print out of a 3D model. By replacing the paper with a thin layer of powder we are able to do just that.

Of course there is more to it than that and there are different technologies that might work a bit differently but I think the way I describe it helps people unfamiliar with 3DP to at least have a basic understanding of the technology. What do you think? Are people just nodding their heads at me to be polite or does my explanation make sense?

What other 3DP processes are you familiar with and how would you describe it?

And – do you have an occupation that is hard to explain what you do? What is it and how do you explain it?

Wednesday, April 21, 2010

Where can you find 3D data to print?

We are a bit spoiled at Z Corp because as design engineers, we have access to nearly unlimited 3D printing capabilities. When I design parts for the next generation of printer, I print those out at various stages of development to check fit, style and function. But, I don’t always print MCAD parts. We do a lot of testing so we keep the printers running – a lot. We might be testing a new component or a whole new printer. Either way, it gets boring printing the same old set of mechanical parts. So, we often look for interesting models for printing that can be downloaded from the internet. What constitutes interesting to different engineers is, well, interesting in and of itself. My preference is for exotic automobiles, airplanes, or anything I would consider to be a marvel of engineering. To others, an interesting model might be a Ming vase, Michelangelo sculpture or some other piece of art. If you walked through the building you might see a printed chess set, pumpkin, football, holiday ornaments, Darth Vader, a snowman, skeleton of a foot, hand, or skull, buildings, Mount Everest, and a wide array of geometric shapes.

There are many sources of printable 3D data available for free or for purchase on the internet. One great source for MCAD parts is 3D content central (because we use SolidWorks here at ZCorp). But there are many sites where you can download architectural content, artwork, medical models, planes, cars, people, and just about anything else you can think of. If you don’t have a 3D printer, your interest in these models may be just for curiosity. If you do have a 3D printer, these sites can be valuable sources of data. Data is available in many formats so you will have to select the format that is right for you. I typically look for VRML (.wrl), but 3DS and STL import directly into our ZPrint® software.

Doing a search for free vrml downloads or free 3D models will result in a large number of sites offering free 3D data. I recommend downloading a few files to determine if the site is worth bookmarking. Below is a sample of sites that I have used.

So, as always, I’m curious. If you download models, what is your favorite site? Do you generate your own models or download models someone else has created? Have you ever paid for a model? What formats have you downloaded. And, what has been your overall experience with downloaded data?

I recently came across the following blog that lists many of the sites that I have used over the years:

Some free sources of 3D data:

There are some very good pay sites also where you can find free downloads.