Preparing a ventilated protective mask for Airsoft

Homemade ventilation mask

Eye protection is mandatory in airsoft, but most masks do not have enough ventilation, so you end up with very low vision by condensation on the policarbonate plastic.

As others have done before me, the trick is to introduce fresh air with a small fan and battery; I used a fan from a notebook computer, with a small switch and a 18650 lithium battery (4.2V) in the corresponding adapter .

First of all I did was improve the ventilation opening the holes that had been semi closed by factory (for Burr plastic injection mold being so small):

We can do it with a cutter or with the hot tip of a soldering iron, which melt those small surplus, as you can see in the picture below.

I recycled a fan of a notebook, being thin and powerful so it works very well with the 4V that the battery is giving; it will create a small amount o air breeze, enough to renew the air between the eyes and crystal.

I've placed it at the bottom, so that the air is introduced through the lower ventilation holes. The air is introduced directly from outside , if it didn't have front openings, they could be made ​​with the soldering iron, thus I can cover the upper side of the ventilator to keep out the moisture from the breath.

Looking for the best position for the fan, see the front openings through which it will remove air

To hold it the best way, I use the thermogluer, which is great for holding assembled parts of plastic such as polyethylene, which the silicone or epoxy does not work very well. 
We plugged the fan on the side with the same gluergun or duct tape, to force ventilator to suck air from outside. 
Finally we put a switch in the middle of one pole to the battery polarity of the fan cables.

Note: This type of fans, unlike those seeking on one hand and ejected on the contrary, operate by inertia; that is, they deflect the air to the outside of the blades, and the air by its own weight gets out laterally, dragging air from either side. They tend to be more durable as their shaft bearing suffer less .

The battery is placed a little lower, avoiding the chin. Finally the total added weight is about 100g. Also you could place a power cord and battery on a pocket .

After testing it, it ventilates well and there is no more condensation from perspiration, but now the problem is that the glass of this mask deforms the image a little... :)

See you later!