A rapid prototype...of a blog post

 
I've worked with rapid prototyping technologies and equipment for a while now, but this form of a quick and cheap fabrication of ideas is a first for me.  I'm not a writer by any means, so this medium is quite new, but if it's anything like model prototyping, 3D printing, or rapid design then I think I'll be OK.  To give a bit of background on myself I am a second-year mechanical engineering student in Missouri, USA, with a love for 3D printing (I own a printer myself), modeling and animation, and any accessible and shareable science, engineering, and electronics projects.  These posts will be my way of working through projects, news, and ideas for myself, and hopefully I can make it an entertaining and educational read for you, too!

  For those of you who aren't familiar with this magic "3D printing", it's not nearly as complicated (or all-powerful) as you might think.  Most printers that the average individual is used to seeing is an FDM printer, which stands for Fused Deposition Modeling.  In this process molten plastic is Deposited in a programmed toolpath, Fused on top of another layer of material, to form a computer generated Model.  In practice this all just comes down to simply stacking layers of hot plastic on each other to make an overall shape (I often liken it to a "glorified hot glue gun").  The process usually takes anywhere from 30 minutes to 10+ hours depending on the size of your model, but unlike traditional manufacturing methods complexity is non-issue.  Additional complexity of an object adds an insignificant amount of time to the printing process.  For this reason (among others) rapid prototyping has really taken off in sectors dealing with complicated, one-off parts and pieces.

  My favorite example of using rapid prototyping to create complex shapes not achievable by traditional means is that of unique human and animal bone structure  recreation.  Recently the teams at the University of Missouri College of Engineering and College of Veterinary Medicine partnered up, taking CT scans of an animal in need of surgery, printing that animal's bones around the target area, and using those bones to practice the exact surgery.  This process greatly increased the chance of success for the operation by giving the doctors a way to practice which would have been impossible without this technology.  Normally it would be near impossible for even a skilled modeler to replicate the unique structure of that particular animal, but by taking and converting the data from the CT scan into usable model information a direct replica was able to be produced.

  This project was not done with an FDM machine, however, but instead used an SLS (Selective Laser Sintering) printer.  In the SLS process a vat of powdered material (normally materials such as nylon or metals) is fused together by a high precision and high intensity laser.  This is then repeated until all layers of the piece are fused.  After the part is finished it is post processed, with all the surrounding powder cleaned away.  This additional powder, which surrounds the entire part, serves as support material for the model.  With this SLS can produce structures with large overhangs, a feature that is often difficult for FDM machines.

  In addition to FDM and SLS processes there is also the SLA (stereolithography) process, which utilizes UV-curable resins, and various methods based on the layered binding of powders.  These make up the vast majority of 3D printing (or "additive manufaturing") methods, while FDM machines are often the most simple and affordable, explaining the recent flood of them in the consumer market.

  I hope this is enough to get you well introduced to rapid prototyping techniques, I'll inevitably dive into much that the area has to offer including materials, major companies, new technologies, applications, my own experimentation, and much more!

- Cam