AURA is the All Users Robotic Arm that you can create at home for 50$. All the information to make this robot, program it and more is in: http://aivrobotics.blogspot.com/
Check it out in: https://www.youtube.com/watch?v=5_OyClmqwb4
I strongly encourage people to make it, to improve it, to adapt it and to use it as starting point in bigger projects.
Degrees of freedom : 5
Maximum operative radius :30cm
Maximum gripper width : 6,84 cm
Total cost : 39,83 euros (around 50$)
Holder Board: http://www.thingiverse.com/thing:284847
Building instructions in: http://aivrobotics.blogspot.com/
In the files there is the project that explains every detail of the design and the constraction of AURA(Spanish Version), and the drafts to describe it and built it .
The robotic arm is composed by 13 printable parts, 5 servos and a microcontroller. Every part needs to be printed just once except the "Phalange medial" that is doubled. The arm A, B and C are diveded into several pieces due to printing problems. You can print them at once or in their pieces and stuck them with cyanoacrylate.
The axes are made with the 3mm filament of the printing plastic, thanks to "jasonwelsh" that give the idea, Check his thing:(http://www.thingiverse.com/thing:116571).
Non printable parts:
Arduino Leonardo (microcontroller)
Servo Corona 939MG (servo m)
Servo HK15288A Analog BB/MG (servo beta)
Servo VS-11 Vigor Extra Large (servo alpha)
Servo Turnigy TGY-R5180MG (servos omega and gamma)
For further information visit : http://aivrobotics.blogspot.com/