Complete How-To-Build video: https://youtu.be/doCg0k0m-dA
This project came about because I wanted to have a cordless fume extractor. The extractor can be powered from either a 12VDC wall adaptor Or 3x 18650 lithium batteries making it rather unique. To prevent the batteries from being over-discharged & to prevent both power sources from competing to drive the fan, a low volt disconnect I build in another video is used. You can learn more about the Low-Volt-Disconnect here.
If both power sources are present, by default the fan will run from the batteries. In an ideal world, I'd prefer the power adaptor to be the default power source. But hey, in reality, I'm only going to use the pwr adaptor as a back up if the batteries run flat.
Selecting a high-performance 140mm fan is very important. The fan I used can be found below under components. However, you could select any other fan with similar performance figures.
For comparison, these are the specs of the Noctua fan I used:
Airflow: 158.5 CFM
Static pressure: 10.52 mmH20
How effective is the filtration? That’s a good question. I don’t have specialized equipment to measure the air quality, however, I’m certain it doesn’t filter everything since I can visibly see some smoke exhaust out the back of the extractor.
So does that mean it’s useless? Well not in my opinion. In my workshop, all I had to do was prevent the smoke from concentrating around my immediate work area. And this fume extractor does just that, it sucks away the concentrated smoke and blows it away from my work area.
The housing for this project is entirely 3D printed. And the 3D files can be found here: https://www.thingiverse.com/thing:4597398
3D Print one of each except for the enclosure files. You only need to print a single enclosure and you must choose one that suits your power switch size, there are 16mm, 19mm & 22mm variants and there is also the option to print an enclosure that doesn't have any switch or DC power jack holes. This way you can print the enclosure and dill/cut holes to suit your hardware.
If you purchase any products using the affiliate links below, you are helping support my content and that makes you awesome! 😎
Noctua Industrial 140mm Fan, 3000rpm: https://amzn.to/3mv9R0r
Carbon filter sheet (cut down to 138x138mm): https://amzn.to/2Flp837
3S 18650 battery compartment: https://ebay.to/3hxUXCA
16mm DPST On/Off switch: https://ebay.to/3kjVhHa
5.5x2.5mm DC power jack, female, panel mount: https://ebay.to/3c13ywC
SB540 Schottky diode: https://ebay.to/3mwWvke
Low volt disconnect: https://www.schematix.co.nz/forum/how-to-s/low-volt-disconnect-project
Optional: 12VDC, 1A wall adaptor: https://amzn.to/3c1maN1
8x 4g 12mm countersunk, self-tapping screw (used to assemble the enclosure)
4x M4x40mm countersunk, screw (used to mount fan)
4x M4 nyloc nuts (used to mount fan)
4x 4g x 6mm pan head screws (Mount LVD to enclosure)
4x PC fan screw (secures the battery compartment to enclosure cover)