Here is the best way to use the materials available off the shelf in Swaziland to make a Rocket Stove for a No. 25 cast iron pot. The device shown is only the fuel magazine and combustion chamber, not the rest of the stove.
The components may in future be insulative but the construction will remain the same. All the components are made from fired clay which together cost less than $7.00. The animation shows all the parts correctly with a gap for mortar, usually 4 to 5mm.
The file can be viewed with Internet Explorer. If you need a particular view it is possible to deconstruct the file to get one frame to study.
ANIMATION - TO RESTART VIEW->REFRESH or F5
COMPLETED STOVE COMBUSTION CHAMBER