I've been having the same thoughts about adding a depostion tool to my router for a while now.

It's going to be a while before I get some free time to experiment with nozzles and such, but I am keen to get 3D printing support into CamBam at some point.

My thoughts were to appropriate the spindle control codes M03,M04,M05, Spindle speed (S register) and maybe even tool number from normal g-code.

I can slice 3D objects and fill each slice with nice G01 line moves fairly easily.

Shouldn't be too difficult to cobble something together using standard gcode interpreter, mach emc etc

If anyone is brave enough to test out some g-code on their squirty CNC machine just let me know.

Anyone?

...now where'd they all go?

One more note.

I have had multiple people inquire via personal e-mail if I had cheaply solved the problem of converting a CAD file into slices and then gcode. 

Of 6 e-mails I have received since I put up this website, 3 of them asked if I had solved this problem.

Again, I apologize for the slow forum response - 4th of July and all.  If you look, you are the only person other than myself to post!  People seem to be reading the posts, however...