3D printer & CNC design

Hello,

I'm new at "DIY 3D printer" stuff and I would like to ask you a question about what design it should have. I want to build a 3D printer/CNC combo machine but that damn design is a problem here. First I taught that I should make something like a regular 3D printer ( the printing head moving on 2 axis and the bed on third) but an issue appeared..... is it ok to bring 1kg of wood or aluminium that high? (I want to build something quite big). The problem with this design is the fact that it double the space required with at lest the printing height and I don't even know if the NEMA 17 motors that I have can handle the weight of the CNC drill.

Can anyone give me some ideas ? But please, don't say something like build 2 different machines because this is not an option

I didn't find the right solution from the internet.
References:

http://3dprintboard.com/showthread.php?31847-3D-printer-amp-CNC-design

app trailers