Replicator 2 tuning: improve main PCB & motor drivers cooling

The bottom of the printer holds main PCB + 4 motor drivers. Air flow is not designed in a best way. This tunning will use a fan to improve cooling. A special electronic circuit is used to sense temperature and to drive fan in a smart way. Circuit is also limits voltage by 12v to use a regular 12v 80mm fan (from any PC store) by sourcing from 24V. Power source 24V is available on replicator main PCB (you can find marked hole to be soldered + you will need similar hole marked as GND).
It is also good to glue (using thing double glue tape) a small sink to a driver like you can find on the photo above. Just make sure that you will not short circuit anything on the driver.
Files needed to make a circuit you can download here http://radiokot.ru/circuit/digital/automat/76/01.zip. It is quite simple. Russian article about circuit is published here http://radiokot.ru/circuit/digital/automat/76/ (automatic translation to English is here http://translate.google.com/translate?sl=ru&tl=en&js=n&prev=_t&hl=ru&ie=UTF-8&u=http%3A%2F%2Fradiokot.ru%2Fcircuit%2Fdigital%2Fautomat%2F76%2F)