I'm completely clueless about electronics. Can someone tell me how to mount and power a fan, what kind of fan I need to get, and what is required to power it??
A good place to start if you have one around is your local Radioshack. You'll want to use the small computer fans most likely (something 9V or smaller).
Mounting can be done by driving screws through the mounting holes if your build has a sturdy enough spot for that. Another possibility is to embed thin, threaded rods to slide the fan onto (again using the mounting holes) and then secure it in place with matching nuts. You could also carve a track for the fan to slide into place and have a tab or stud to secure it. As for where to mount it, that depends on the helmet. Popular choices are to make use of the helmet's existing "vent" locations or if there's room in the brim/visor, put it there and maybe drill some very small, inconspicuous holes in the underside of the brim/visor to facilitate airflow.
Providing sufficient power will depend on the voltage of the fan, as well as how many fans you will have on that same circuit. The same goes for lights, or really any electronics. And that thread is probably the best place to go for answers on that front because I don't have a whole lot of experience there, as depending on size and number of fans and what kind of battery setup you'll have room for you may also need to incorporate resistors to regulate the power so you don't burn out the fan or have to change batteries every couple hours. Again, it's best I let more experienced members handle answering that question, and within the existing posts on that thread you may find the answer has already been given.
