This is Brendan, just wanted to say hello. After a lull I'm back working in the last month and will post again soon. My project is focused on making a heliostat as cheap as possible so I've got gear motors instead of steppers (with hall sensors to count rotations) and a cinderblock base and things like that.
I have a Makerbot cupcake (which I'm now mired in trying to do an upgrade on) and it has really changed my perspective on design. Before I got it the design was driven by leveraging parts I could buy. Once you know you can make, for example, gears of the size you want, it frees things up a lot.
Gabriel, if you're looking to buy a 3D printer the market has opened up a lot in the last couple years. I love makerbot as a company and they have a new bot out (Replicator) with an 6" x 8" build area but you'll also want to consider an Ultimaker (8" x 8" build platform with better resolution which is important for gears and such) and Cubify and others. There is a good google group for makerbot which has nice honest discussions from people considering different printers. The possible game changer of the Replicator is that it has two extrusion heads so that you could extrude a water soluble material out of one of them which opens new possibilities. With your design and CNC experience, you are going to love 3D printing.