I love rocket stoves... For those that don't know it's a great way to cook with wood. The basic principle is to burn wood hot and fast, which is more efficient. So you insulate the fire and direct the heat to where it's needed... The pan!
Work gloves are important, this involves lots of sniping of sheet metal and it can be a painful if you don't wear gloves!
I guess you could make a rocket stove out of anything, but these 20 litre oil cans are perfect and very common in the UK, very easy to find in the street.
Again, you could make the burn chamber and stack out of anything, and in fact a 90° corner to the burn chamber is better... But this 4" flexible flue is easy to work with and I had some lying around, so that's what I used
This isn't aluminum dryer flue, which I'm guessing would burn out fast, but stainless flexible flue designed for a chimney stack. You could use anything, I've seen people get clever with normal sized tin cans.
The pot for the rocket stove needs to fit pretty snug, a 1cm gap around the edge is best. The pot shouldn't have any plastic handles or anything as they will melt. Also a good fitting lid is important, as we all know that things boil quicker with a lid! I prefer a pot with two small handles on either side, rather than one long handle, as it's makes a smaller footprint when in storage.
I used sawdust as the insulator, you could use anything that's a good insulator that's fire proof. I've heard of people using vermiculite. I like sawdust because it's free and I quite like the fact it's heavy, makes the whole stove way more stable when in use. But it's pretty heavy to move around!