Thanks to the discussion I read on the http://cube3d.createaforum.com/general-discussion/crap-hack-bulk-filament/
thread, there is a tool called CodeX which can encode and decode the .cube files into actual gcode, the instruction set that gets processed. The tool is available at https://groups.google.com/forum/?hl=fr#!topic/kisslicer-refugee-camp/ZMuIrtn5Mfo
I have a 2nd gen cube as well. I used the bulk filament trick successfully but found that I needed more control than what the Cube software offered, specifically ability to control heat. 3D Systems seems to do everything in it's power to prevent us from using the system effectively. My co worker has a couple of 3d printers and has a lot of experience with slicers and settings and was shocked that we don't even have the ability to specify a temperature.
Using the Codex tool, I was able to decode a .cube file by selecting Cubepro as the format and specifying the .cube file. This decoded it to a .bfb file, which is simply a text file of gcode. The headers are set specific to us. Cube:2 means 2nd generation cube. Type:1 means PLA, 0 means ABS. Time is the (estimated) number of minutes for completion. I am still trying to understand the Material value, maybe amount used?. Here is an example from the file:
The rest below it is GCode values for the printer. GCode itself is nice and well documented, http://reprap.org/wiki/G-code
. Other slicers will allow for more control (if you can configure the printer settings to match the Cube system), but it will have to have these headers specified in order to work. The google groups thread had a guy testing and if the values are removed or incorrect, it fails to decode on the printer. I've been decoding and modifying the temperature setting so far so I don't have any alternative slicer experience yet, but if you take a gcode text file (with these headers) and encode it to .cube using the codex tool with the cubepro setting, that should allow you to use any slicer that you want.
Best of luck to you.