Sorry guys forgot to get back. 9v off the board didnt have enough current to drive the fan/move much air. What I ended up doing was buying a cheap 240v to 12v converter, wired than into the mains feed to drive the PC fan. Obviously mains voltage can be dangerous so know what you are doing.
Essentially my version of this incubator was crap. Heat from the standard fan overheated the eggs if I insulated the incubator. If I didnt insulate it there was up to four degrees variation in temp from the centre to the edge. I have it going okay now but only after much trial and error, tinkering and a few failed hatches.
Would not recommend anybody purchase this incubator.