Dragon Breath

Please be aware this is not a beginners project.

Please take the necessary precautions and care.

The e-cig needs a high current and works at a high temperature.

The smoke is also hot.

My friends Polly and Chris enjoy Steampunk things - they are fantastic at making the costumes etc. but wanted a dragon that breathed smoke - they could make the dragon, but the smoking part they were not sure about.

The casting of the head and the making of the dragon is shown in another project.

This project shows how I hacked an e-cig and added some LEDs and controlled them using a remote control. (See the article How to remote control a Thing.) 

This is the "atomiser" end of an e-cig. The black part is the mouthpiece. A battery screws into the other end. The clear "bottle" holds the liquid that will be vaporised. Instead of using anything that smells or contains nicotine, I used food grade vegetable glycerine.

There's a pin inside the e-cig:

Using needle nose pliers, remove the central pin. I made sure the pin was clear of any glycerin by cleaning it with IPA (Isopropyl alcohol). A better way would be to take it apart *before* testing it works!

Note - it is not necessary to take the atomiser completely apart!

How the e-cig works: Electricity runs up the inner pin, and conducts to the small metal wire wrapped around the bundle of "string" and then out to the outer part of the e-cig (third part in from right). The wires heat up like an incandescent lightbulb. The string wicks the glycerine up to the heated part, where it vaporises. Air passing from the bottom of the atomiser (the right-hand side) causes the vaporised glycerine to pour out of the mouthpiece (black part).

Solder a red wire to the pin. Use a relatively thin wire.

This is the hardest part as the solder does not stick to the pin easily. Tin the red wire and the end of the pin - be careful not to block the hole - this is where the air goes in.

Heat the pin with the soldering iron (make sure there is solder on the tip), then place the red wire on it until the solder joins the two.

Again, make sure the hole is not blocked. 

Solder a black wire to the outer e-cig body.

Make sure the inner pin, any solder touching it or the metal wires from the red wire do not touch the outer e-cig body when re-assembled.

Air Pump.

The other ends of the wires are soldered to the air pump.

Re-assemble the e-cig.

With care to line up the output of the pump with the air hole by the central pin of the e-cig, hot melt glue the pump and the e-cig together. I found this to be very messy and difficult to get right.

Add the glycerine. It goes in through the mouthpiece. Do not overfill - half full is more than enough.

The wires from the air pump will go to the Thingatron, which is controlled via the Remote Control a Thing system. The e-cig battery is connected to the Thingatron, and power to the e-cig and pump is only applied when the Thingatron is switched on.

A silicon tube, and a "Y" adaptor channel the smoke from the mouthpiece to the nostrils of the dragon.

This is a Thingatron. Another output pin from the Trinket on the "Remote Control a Thing" goes to another Thingatron (built on to the veroboard) which controls two sets of LEDs - one set for the eyes and the other for the nostrils.

Random notes:

• I programmed two buttons on the remote -  "A" does LEDs and smoke, button "B" just LEDs
• To stop overheating, I programmed in a delay so you can’t re-press the buttons for 30 seconds
• You need to run the smoke about three times before it comes out - once there’s smoke in the tube, it’s fine.
  
  

Remote Smoke video

Articles in this series

1. How to Remote Control a Thing - make the remote element
2. Dragon Breath - electronics for the eyes and smoke
3. Experiments in Casting a Dragon - creating the mould