The survey for my next project has been closed. I'll have a video posted shortly detailing the winner and my plans to create it!
This is a 3D Printed R2D2 powered with an Arduino. I started out sketching things on note cards, after that I looked up a bunch of reference images on Google to work out the dimensions, then I went to Tinkercad to start modeling it out. After that I printed the parts out using PLA on my Robo 3D Printer. The biggest prints are the body that took around 10 hours and the head that took about 6 hours to print. The rest of the parts took anywhere from 2-3 hours. The whole project totaled about 30 hours of printing time. I printed everything at 0.3mm layer height but the quality can be improved if you decrease that.
After it printed I handed it off to my wife so she could paint it. She picked up some plastic spray primer to help the paint stick. Then she painted on the details with acrylic paints and a brush. Then she gave it a clear coat afterwards to avoid damage to the paint job.
It has 2 stepper motors to drive it, a servo motor to turn the head, a bluetooth module for communication, and an LED for his head/eye. You can check out my breadboard layout and code below.
Disclaimer: This isn't a fully completed project, so make sure you have fairly good knowledge of electronics as it will take some upgrading to get working 100% correctly.
I have a video posted that details the assembly process a bit more and have links to all the components I used, link to it in the video on this page.
I had a lot of fun making this. If you build one I'd love to see it! I'm also going to be adding another project on here that is a non-electronic version of R2D2 in case you just want a cool looking R2 sitting around. :) http://www.thingiverse.com/thing:1213273