Filament Joiner

If you have a 3D-printer. You will sooner or later want to join filament to be able to use up all your stumps you get. I decided to take on the problem and this is what I came up with. I know that Rich already designed a nice joiner ( http://www.thingiverse.com/thing:9850 ), but that requires that you have a heat resistor and that you use the computer (software) to control the heat. This results in that you cannot join filament while you are printing. :)

PS: The Sketchup file is just an examp