Between school and work, I’ve spent quite a bit of time around syringe pumps. They’re simple things, consisting of a single stepper motor, a controller, a syringe and some tubing, but they allow for very consistent flow of just about anything you can squeeze through a hole. Ever since I saw RichRap’s work on paste extrusion, I’ve been itching to try it out on a 3D printer. check it out for yourself: http://richrap.blogspot.com/2012/04/universal-paste-extruder-ceramic-food.html
This is my first shot at a paste extrtuder; all files and source are released under CC4.0, share alike license.