The secondary air jets are 16 evenly spaced holes with diameters of 5mm each. The ring at the top I made out of a dump yard CD-ROM Drive casing. It is to block the air from running straight through the gap between the outer can and the inner can. The bottom of the can looks like this:
The holes make out part of the Adjustable Primary Air intake. When the inner can is turned on the plate on which it stands inside the outer can, the Primary Air intake is adjusted. Here is a photo of the matching plate inside the outer can ( plate cut from CD-ROM-Drive cover plate ):
The plate on the inside is standing well away from the bottom on wire paws. When the inner can is inside the outer can this is what happens when you turn it:
Effectively the Primary Air is adjusted that way. The wire mesh is just to keep the sticks from falling through.
For the fan I used a small DC motor from a broken CD-ROM drive. ( handy old broken CD-ROM drive huh ? ):
For the propeller of the fan I used a round piece of metal I cut from the cap of a jar:
The motor will work well with 3 Volt. I modified an old cellphone battery to use as power source:
The dip switches switches in various resistors to give various fan speeds, but 2-3 speed is usually enough. The one plug is where the fan plugs in the other is to plug in a home made solar panel to recharge the battery.
Here is a photo of the whole setup: