I needed a small battery-powered fog machine for an upcoming project. Mains-powered foggers are not at all expensive (~$40). But a battery powered portable one is, for reasons I don't really understand, a whopping $800 (or even $1850!). There are various wimpy fog machines like the Wizard Stick (kid's toy) and the Dragon Puffer (same device, repurposed for draft-testing), that don't generate much fog and need to be held upright. But I wanted a battery-powered fog machine that was silent, had variable output from a few wisps to a dense cloud, and could be waved around. This ruled out any commercial fog machine I could find, so I designed and made one myself using an electronic cigarette, a small fan and a 3D printed enclosure. Just the thing for your Halloween costume, product staging, or party.

Step 1: Parts and Design Rationale

You will need to acquire the following:

- electronic cigarette kit (I advise buying extra emitters). I used a TW INTU E-cig kit, with a 5000 mAh battery, variable power up to 80 W, and a 4 ml tank.
- battery holder for 3 AAA batteries
- 3 AAA batteries
- 40 mm 5 V computer fan
- a rocker switch
- a 3D printed enclosure (see next step)

Total cost <$100 if you have access to a 3D printer.

You can find other e cigarette fog machine hacks online, but I experimented with them and found them noisier and less foggy than I'd like (e.g. this one that uses an aquarium pump). Hence the new design.

Step 2: 3D Printed Enclosure

The enclosure is 3D printed, and the STL file is attached to this step. It was designed with Fusion360. It can be printed with any material you have on hand. It needs supports to print, but you could chop the file up, print each piece separately and glue it together (E6000 works well I've found) if you'd prefer. If you want to tinker with the file yourself, it is available freely online. This might be handy if you want to adapt it for an electronic cigarette you already own, for example. Just move the walls around.

NOTE (23 November 2016): I will be publishing a new enclosure for this soon that uses a rechargeable battery. Stay tuned!

fogmachinebody.stl
Download View in 3D

Step 3: Electronic Cigarette

Follow the instructions for assembling the e cigarette: it all screws together pretty logically and the fluid goes in the glass chamber. Charge the battery, add some fluid, and set the wattage fairly low (say 20 W; this unit goes up to 80 W, which will make it get hot and splutter, generate a ton of fog, but burn through your fluid really fast).

As far as I know, nicotine-free vaping fluid is essentially the same as the fluid that gets put into fog machines, except it is flavored. Obviously, just buying regular fog fluid is going to be vastly cheaper than buying the vaping stuff 10 ml at a time.

Step 4: Assemble

You will have to do a little wiring - I soldered the connections and added heat-shrink tubing. If you don't have access to a soldering iron, you could simply twist the wires together and secure with electrical tape, but your connections will likely be weak. Small connectors would work, too.

Add 3 batteries to the battery pack, thread the wires through the switch hole, and install the pack in the enclosure. Do the same thing with the fan. Wire the red wires to each other, and the black wires to each pole of the switch (I removed the wires from the switch and soldered the wires directly to the switch). Put all the wires into the central cavity and press-fit the switch into the slot in the 3D print. That's all there is to it!

Step 5: Use

To use the smoke machine, fill the fluid reservoir in the e cigarette, restore the cap, and insert into the 3D printed enclosure. Start the e cigarette by pressing the large button quickly five times. Start the fan. Use the +/- buttons to set the wattage. 10 W will provide a small amount of fog but will be sustainable for a much longer period than say 60 W, which will pump out a big cloud of fog but will make the e cigarette get hot and burn through your fog fluid quickly. It's easy to tune for whatever volume of fog you need. All the pictures in the instructable were obtained at a setting of 30 W.

The e cigarette will not allow continuous operation for more than 10 seconds without depressing the button again (a safety precaution to avoid overheating).

To check the fluid level, either slide the e cigarette out or switch on the fan and look through the blades with a light behind you. More generally: if no smoke is generated when the fan and e cig are on, you're out of fluid!

If you make one of these, post a picture and I'll send you a premium membership to instructables.com.