How do you add another extruder to a prusia I3

[pilotkid2014]

Hello all, I was wondering how do you add another extruder to a prusia I3 How do you control the other extruder is it just one board or is there multiple boards and how do you send info to it?

[3dkarma]

1. Have a look on Thingiverse for dual extruder designs for the Prusa i3 and choose one that suits your hot end or the hot ends you want to have. http://www.thingiverse.com/search?q=...l+extruder&sa=

2. How you control the additional extruder depends on the capabilities of your board. The most common board is RAMPS; you'll need to wire up the additional hot end and thermistor and connect the additional extruder stepper to the board: http://reprap.org/wiki/RAMPS_1.4#Wiring. Remember to power off the printer before changing the wiring. You'll also need to change your firmware configuration to support additional extruders. If you're using Marlin, look for the extruders line in configuration.h and increase the number from 1 to 2. You'll also need to set the distance or offset of the extruders from each other in X and Y (measure and tweak as needed). If you're using Repetier, configure new firmware at the repetier site. Of course, all this depends on what board you have.

3. How you send info to it, or how you print with it, is to:
a) Create two STL files for the piece you are going to print - one for one extruder, the other for the other. Look at this three color cone on thingiverse: http://www.thingiverse.com/thing:766265. The second and third diagram show how the print is made up of two separate files. Note that both of them start at 0 on the X axis. This is important or your parts won't mesh properly.
b) Start up Slic3r (this is the one I know best, so this is the one I'll describe) and change your printer settings to add an additional extruder. You'll see settings for extruder 1 and extruder 2 appear. Make sure you get the settings right for each, including offset.
c) go back to the plater pane and you'll see there are now two combo boxes for filament. Make sure each is set correctly.
d) Click on File, then "Combine multi-material STL files". Select the first file you'll be printing (extruder 0 will print this) and click on Open, then the second and Open again. Click Cancel and you'll be prompted to save an amf file, which combines the two STL files into a multi-material print.
e) To slice the print, load your newly-created amf file into Slic3r and print it.

There's lots and lots of tweaking and tuning you'll need to do to get dual extrusion working properly and you'll be fighting ooze and all kinds of issues, but it's worth it in the end.