Are there LEGO compatible CAD Files For Injection Mold Manufacturing? I've designed some fun building brick sets that are compatible with LEGO but I know the market for them is smaller than what LEGO would be interested in.  I've contacted some manufacturers at alibaba.com to see if they could produce the sets for me however most of them want me to send them 3D model files.  

I can convert the LDRAW files to OBJ files, but are they accurate enough for use for manufacturing?  Has anyone else tried this?
Look here: http://www.thingiverse.com/tag:LEGO

But be aware- as a single person manufacturing a LEGO compatible item, you might be open to litigation. You would probably win, but winning very frequently bankrupts people either way. Do you really require a unique piece that LEGO does not make? There are many custom sets around that are a kit of LEGO manufactured pieces.