Hello,
I just build my first 3D printer, a Huxley from reprappro.
I found some info here:
1) [
www.tantillus.org]
look at the pictures
with the Marlin/Melzi delivered recently by reprappro, you change the flow with the G-code M92 Ennn...and it is automatically saved in Eeprom.
2) for the temperature I found a nice explanation at the end of reprap.org/wiki/Triffid_Hunter%27s_Calibration_Guide
3) a cooling fan is sometimes needed .
I installed a littlefan 40*40*10mm. The internal electronic circuit of the fan does not run with PWM (when M106 Sxxx has a value < 255).
With a low-pass filter it is running at varible speed and safe (fan designed for 12V): resistor 68R + capacitor 100µF.
I use Pronterface + Slic3r
Robert