How to make a model rocket engine from scratch?

Question

as i said

Answer 1

You will need to investigate the chemical mixture to use, there are common ones like black powder (Potasium Nitrate [saltpeter] + charcoal + sugar) I used to buy saltpeter at the drug store (in the olden days they gave it to boys to reduce sex cravings...) but I don't know if it is available there anymore...

You need 2 other components besides the fuel - 1. A nozzle, and 2. An igniter.

The simplest nozzle would be a straight hole drilled through a plug (that would close the bottom of your cylinder rocket body full of fuel). But a point to point cone shape would be better. Another alternative, I saw a design for a model rocket which used an empty CO2 cartridge (like a BB Gun would use) the cartridge end is very nozzle like and you just fill it with your fuel.

For the ignitor, there is something called nichrome wire, it is a thin wire that when you attach a battery to it, it gets hot (even easier though, they sell little ignitors at hobby stores for estes type model rockets.) You would have to mount the ignitor into your fuel and plug up any remaining space so that the fuel doesn't fall out...

Answer 2

Cakes are made out of scratch, to make a rocket you'll need to get a solid rocket motor and some metal tubing. If your just starting out, as obviously you are because you did ask the question, you should try some models you can get at the hobby store and work your way up from there.