Tuesday, January 31, 2012

Thesis Statement

 I decided to start this blog to document the progress of my thesis. It's also an easy way for friends and family to keep up with what I'm doing.  For those of you not familiar with 3D printing, read on and it will start to make sense.

To start, this is directly from my thesis paper:


The goal of this project is to design, model and 3D print a highly-detailed, underwater vehicle patterned after an octopus.  The final presentation will be a fully articulated, 3D printed model, using various materials.


Deep beneath the waves, a barnacle-covered shipwreck sits on the ocean floor.  A spotlight cuts through the murk as a metal tentacle appears and pries off a rusted door. Another tentacle slithers through the opening; emerging with a corroded safe.  The treasure is pulled back toward the source of light; a giant octopus vehicle.  Crew members man the controls behind giant eye-like cockpit windows.  A claw emerges from underneath and pulls the safe up inside the vehicle and the ocotpod shoots toward the ocean surface.

The project will involve designing and modeling an underwater salvage vehicle based on an octopus.  The final presentation will be a physical model, including a display stand, produced on a 3D printer. 

Inspiration for the vehicle design comes from World War II and Cold War era design esthetic, as well as references such as the Nautilus submarine from the 1954 Disney movie, 20,000 Leagues Under the Sea.  The model will be very mechanical, with hoses, pipes, dials, rivets, cooling fins, etc.  


While my thesis is primarily a modeling project, it will also be produced as a physical model.  How I model the octopod will be directly informed by the requirements for 3D printing and the capabilities of the printer.  With this in mind, I need to explore 3D printing technology and the construction methods required for a successful print.

The process of 3D printing is accomplished by taking a digital model and virtually slicing it into layers that are sent to an object printer.  The printer uses the slice information to lay down thin layers of plastic or other material to slowly build the object from the bottom, up, resulting in a physical model.  

3D printing is being called the 'next industrial revolution' and rightfully so.  A technology that allows you to take a digital model and 'print' it as a real-life object sounds like sci-fi but is now accessible to everyone.  It is typically referred to as ‘rapid prototyping’ and has been around for at least 20 years, so why is it just now starting to boom?   Recently, the cost of printing machines has dropped to where you can have a basic one in your home for around $1200.  In addition, companies such as Shapeways offer online services where any user can submit a digital model which Shapeways will print out in a variety of materials.  Shapeways can be used as a personal print service or you can open a shop and use them as a print-on-demand service for your own customers.  Originally used for strictly industrial purposes, this technology is now being used to make everything from toys to prosthetics and is, without a doubt, the next big thing.

You will see the terms 'rapid prototyping' and '3D printing' used interchangeably, but what is the difference?  From what I have observed, 'rapid prototyping' usually refers to industrial or product development applications, where a prototype of a part or product is needed.  It's used to work out logistics and viability, but the final product is typically made using traditional methods such as machining and molding.   ‘3D printing’ is generally used in the hobbyist and consumer realm where the item printed is the finished product.  Using these criterions I will describe my thesis as a 3D printing project.

To realize my project, I will be utilizing the Objet Connex 500 printer at New York University's Advanced Media Studio (AMS).  This machine is capable of very high resolution, large print size and can print with two materials simultaneously and even mix them to produce hybrid materials. Due the fact that this is such new technology, I found that the easiest way to nail down the technical details was to interview the people who do it.  CADA Adjunct Professor Erol Gunduz introduced me to 3D printing and has been an invaluable asset.  I have consulted with Erol many times to form the following workflow.  In addition, Taylor Absher and Andrew Buckland, both Technology Specialists at the AMS lab have provided incredible guidance and feedback for my design and potential workflow.

I plan on constructing the octopod in Cinema 4D and ZBrush.  While Maya is the industry standard, I feel that Cinema 4D provides some particular advantages for this project.  I find the modeling tools to be easier to use and more flexible than those in Maya, particularly the symmetry function.  In addition, the boole functions, which are vital to this project, simply work better in Cinema, producing cleaner and more predictable results than those in Maya.  Finally, Cinema 4D has recently added the ability to model in an exact scale which allows me to accurately design the model to accommodate real-world elements such as the armature wire and LED lighting.

The finished model will be brought into ZBrush to add details such as weathering and damage, and then decimated to optimize the poly count and distribution.  The model will then go back to Cinema 4D where any booling procedures are done.  This workflow is necessary due to the fact that the booling procedure can create geometry that will deform in ZBrush when subdivided or sculpted.  Once the booling is finished, the elements of the model must be exported to separate STL files which correspond to the type of material they will be printed in.  This step is necessary to assure that the printing software correctly assigns the material type. The easiest way to do this is to isolate the geometry into separate files. 

It is vital that the finished meshes be watertight, with no manifold edges or other geometry irregularities which would cause a print to fail.  The STL files will be processed through netfabb and MeshLab, both of which look for and repair such problems.  I have found it necessary to process the models through both since neither tend to catch all possible problems.

The final step is to bring all of the STL files together in the Objet  printer software and assign the desired materials.  The scale also needs to be verified, usually by including a reference cube (ie: cube known to be exactly 10mm).

The finished parts will be assembled, armature wires installed in the tentacles and LED lighting installed. The octopod will be presented on an ocean-floor display stand.