Geir Andersen over at LetsMakeRobots has designed and built this cool solder paste dispenser:

As I’m doing SMD prototypes I wanted to do reflow soldering instead of hand soldering and needed a solder paste dispenser.

The professional ones are not that expensive but you need an air compressor and I was trying to avoid that extra cost and noise. So I came up with this design.

It uses a PICAXE M14 microcontroller and ULN2003 Darlington driver to run the 28BYJ-48 stepper motor. As a stepper the 28BYJ-48 sucks with its gear ratio, but for this purpose it is cheap and has lot of torque. For my type of work and one-off prototypes it works great.