This is a strap mounted blower to keep the fog out of a pair of airsoft goggles. Dissatisfied with my ExFog unit, I decided to build a small run of an improved design. My main complaints with the ExFog unit I bought were it was too expensive, had limited airflow that couldn't keep up with sweating hard outdoors, thin and kink-able PVC tubing, and a lack of clarity on how to best attach the unit to a set of safety goggles to keep them fog-free. As I had already found an airsoft goggle I liked, the Lancer Tactical Aero, I wanted to design a system that would attach to this goggle and keep the lens flooded with sufficient fresh air to keep condensation from forming on the lens in even the sweatiest matches on the most humid of days. This design takes advantage of an inexpensive larger fan that is commonly used on 3D printers, the 5015 blower. Originally I designed this unit to work with the common lithium-ion 18650 battery, but I found my first prototypes with it to be too heavy, so I opted for a smaller 14500 lithium ion battery. The 14500 is basically a lithium-ion AA battery. I used an adjustable 5-12VDC step-up transformer / USB battery charging PCBA to drive the blower, so you can use a 5V or 12V 5015 blower fan, and adjust the voltage to suit the user's airflow preferences.

Parts used:

• QTY 2 - M4x25mm button cap screws
• 5015 Blower Fan - 5V or 12V (https://www.amazon.com/gp/product/B0775ZM4DW/)
• Adjustable 5-12V Step-up / USB charger PCBA (https://www.amazon.com/gp/product/B0B7JGJ67J/)
• Small switch (https://www.amazon.com/gp/product/B086KNZL26/)
• 10mm OD, 7mm ID silicone tubing (https://www.amazon.com/dp/B08PTWPXNW)
• AA single cell holder (https://www.amazon.com/dp/B098782JVV)
• 14500 protected lithium-ion battery (https://www.amazon.com/Rechargeable-Battery-2500mAh-Flashligh-Shipping/dp/B0BZCXSGLH/)

Printed the enclosure parts and split tubing adapter in PETG, with supports as needed (not in the M4 threads, for example), with the lid on its front face, and the strap enclosure on its side. Printed the Lancer Tactical nozzles in TPU so that if they get hit with a BB I won't get plastic shrapnel in my eyes. If you make a similar nozzle for your goggles, please upload it as a remix!

Assembly Video:

Update: Upon request, I've attached the .stl files (fan_only_cover.STL, fan_only_mid.STL, fan_only_power_supply_enclosure.STL) as well as a photo for the prototype I build that uses 18650 cells, with a different switch, and the same step-up / charging PCBA in a belt-clip enclosure. If you're building the newest version, you can ignore these files in your build. I personally found the wire to be annoying enough that I redesigned this prototype into new version that uses the 14500 cell, but if a wire and a power supply clip is more your style, have at it! One big advantage of this is that it minimizes weight on the strap, and maximizes battery life. This unit also uses two unique components:

5mm DC plug & wire (I prefer the 90 degree version here): https://www.amazon.com/gp/product/B0851CV1Y6/
5mm DC jack: https://www.amazon.com/gp/product/B08LQ3SB3F/
Larger rocker switch: https://www.amazon.com/gp/product/B07XC5KB8D/