Think of this machine as a very friendly sculpting spider.
For my last semester as an undergrad at IIT, I decided to give my education a twist and create my own research project. Fascinated by natures way to fabricate, I got inspired to create the Bug, a 3D printer-like robot that can create using composite fibers.
Step 1: Motivations and Inspirations
Fiber composites have been present for thousands of years now, they have evolved significantly into technologically advanced materials that today offer advantages like strength-to-weight ratio, flexibility or even insulating capabilities.
Today, we are living in a digital fabrication era where computers and prototyping machines are transforming our surroundings from mass-produced products into a world of endless customization. 3D printers have played a pivotal role in this desktop revolution, the speed of this additive process, as well as the low waste and relative low cost have made them a most-have machine for engineers, designers and researchers. 3D printers however are limited to layers and the strength of the bond between them, making parts significantly weaker than parts of the same materials made by injection molding, machining or casting. These days the market for 3D printers is getting crowded, and yet the market for fiber composites rapid prototyping has been barely explored.
Most of the inspiration was narrowed form nature, looking how animals and insects are able to create by mixing elements. My trip was also inspired by a trip to the Media Labs, where I saw a an amazing pavilion made by combining brilliant brains and hard working silk worms. If you don't know what I'm talking about you should.
Step 2: Research and Testing
With no time to lose I found myself spending hours trying to come up with ways to do this. Researching different resins I could use, different fibers I should start with, what sort of robot I would move all of these, how I would handle the extrusion of fibers and how they would bond and retain shape.
I decided to go for the UV cured type resins and tested a bunch of them until I found one that would cure fast enough and was able to retain shape. In the picture you can see my testing setup and an extruded thread holding horizontally once exposed to the process.
Step 3: IIT MMAE Department and IIT's IdeaShop
Realizing that I was not going to have enough time to design my own robotic CNC machine I decided I should try to get an existing one. I did some research into some repraps, the shapeoko and others, at the end Christmas came early with the donation by Ph.D Matt Spenko, a Fab at Home, an early 3D printer made by a group of students a couple years ago and left behind in the lab.
I would also like to take this opportunity to thank my advisor in this project, Ph.D. Matt Spenko and my unofficial advisor John Welin at the IdeaShop that not only provided me with tools, but more important, knowledge and challenges.
Step 4: Design. Make. Test. Repeat...
Iterations. As you can see I did a couple until the time was up and I could no longer do more within the original time plan.
At one point I also changed my LEDs for 3W ones, huge improvement in curing time!
Step 5: Generating the Path
At the beginning, I didn't have an efficient way to generate the path, I had to select the points almost by hand. For this reason I came decided that the first print should be a simple 3 dimensional bell curve. I simplified the surface into a series of curves that intersected at the center and decided to give it a shot.
Step 6: First Prints!!!
The first couple of prints were very demanding and time consuming, a lot of monitoring was needed and problems with the Z-belt meant that I had pause the print to readjust the z-axis. The 3rd print however, was very rewarding as the object made looks somewhat to what I wanted to create!
Step 7: Code Generating the Path
Using Processing I was able to grab any 3D model and extract a path for the machine to follow. In the images you can see some of the progress and how it went from a very chaotic randomness to a more smooth organized randomness, if that makes any sense. I also decided that it would work best if the machine would first make a supporting grid first and then it bonded the surfacing lines on top.
Here I would also like to thank John Mercouris for his help and trouble shooting while writing the code.
Step 8: Latest Print!
It has been a long way and I cannot yet see the finish, but the road looks amazing.