Conducting a study on 3D printers open source

Hello everyone !
We are french CPGE Maths Sup students, and during two years we have to work on a personal project. 3D printers seems to be an attractive subject, requiring many fields of competence.
We want to study an open source model, such as RepRap printers. We could try to help the community to improve it, too !
First, we need a model to focus on. Maybe the Prusa Mendel ? Is this a good idea, or another printer could be better ?
We also have to find the way to study it. We only have a year and a half to realise this project and we can’t study the whole printer ! So, is there a part which could be more interesting or need some improvements ?
We are waiting for your advices ! Thank you in advance.
PS : sorry for our english !

Welcome and good luck with your project.

Prusa mendel is a great choice. As is the Reprappro mendel. Don't have much experience with any other printer types.

Metal printing would be fantastic if you guys could contribute to the guys already working on it.
A multicoloured extruder with only one nozzle, one colour filament and a system to bring full colour would also be fantastic...
Software to easily handle multiple colours is also on my list. Although I can only print in one colour at the moment aside from splicing filament.

That's my wish list for now. Thanks Santa

If I had to pick one part to study and perhaps try to improve, I would probably make it the extruder. I think you will find there are more advacnements that could be made here. Rather they be in the cold end or the hot end or both. Maybe a whole new design all together. Perhas conentrate on smotther plastic flow and consistancy with compensation for variations in filament diameter.