Personal Touches: Helmet Fan System

Despite my business trip last week, I was able to get a small part of my armor project worked on, if not an optional part. I brought some parts and my soldering kit with me on my trip to do some work after I was done at the remote job site.

I decided to ape the Echo Fan system used by many TKs using parts of my own, on a budget. Echo Fans typically cost around $70, but I was able to pick up parts for a comparable fan system from Fry's (before my trip) for less than $25. Also before the trip, I used card stock to measure, fit, and trim (repeated several times) a strip that would serve as a template for the backing, to make the system easy to add and remove to the helmet.

For the backing itself, I used some spare vinyl sheeting that I had left over from a previous project. The vinyl wasn't long enough for the entire strip, so I traced it into to halves, to be butt jointed using a third, small strip and CA glue.

After trimming and assembling the vinyl, I broke out the electronic pieces and laid them all out to ensure that I had enough wire to spread everything out. I had two 2xAA battery boxes to be wired in series to generate 6V to run the 12V fans at half-speed. A micro slide switch would allow me to turn the fans on and off as I pleased. I also soldered some leads onto the batter boxes to twist parts together and ensure the design worked, and that I had my polarity correct.

After some experimentation, I decided to put the switch in between the battery boxes, from the positive terminal of on box to the negative terminal of the next box, ensuring that the circuit would be broken with the switch in the off position. I used integrated the quick interconnects that came with the fans to make any future replacement easier if/ when the fan bearings get shot.

Not having the Dremel tool to add the cut-outs to the vinyl for the fans or the switch (which will poke through the back where the electronics are to be mounted), this was all I could do for now. Now that I'm home, I'll fix a cold solder joint, be able to add those cut-outs, and mount the system. The stock by itself is so rigid that it can easily stay in the helmet through flexing tension, but I'll probably be adding H&L to bot the inside of the helmet and the fan system to keep everything in place. I'll cover this in a future entry.