Choosing a Robotic Arm for an Electric Engineering Project

[ffp]

Hi, I'm an electric engineering student and I'm want to initiate a project to control a robotic arm. But i must first choose which arm i will work on and where to buy it.
I want to make a position control, so i will need a feedback of the actual position of the arm. The control will be made with a arduino microcontroler.
I was thinking in the OWI-535 EDGE robotic arm, since it's cheap and small, but i saw on internet that it uses DC motors, and a position control will be very hard to make.
So i think i'll use a servo motor robotic arm.
I want your help to choose a robotic arm that's not very expensive and it's small. Also any advice is welcome.
Since i live in Brazil, i need to buy it on internet in a store or site (ebay) that ships to my country.

Thank you

 

[Danger]

I'm sorry that I can't help you with this, Ffp. Any time that I need something, I build it myself, and I use DC exclusively. (I've never had computer control, though, so that probably makes a big difference.) You can use sliding pots for position sensing, or go with strain gauges or nicked fibre optics. Theoretically, it should be cheaper to build your own, but that might not apply in your area based upon availability of parts.

 

[huntoon]

Saw this on youtube:

C-Control Robot System Fahrgestell Robby RP5/RP6
Playtastic Baukasten "Roboter-Arm"
Arduino Mega - Microcontroller ATmega1280
Arduino I/O Expansion Shield
Arduino APC220 Hochfrequenzmodul
Motorsteuer-IC ST Microelectronics L 293 D Channel Motor-Driver
Software: Arduino, Processing

http://youtu.be/AdYiPQ80Pvc