Solid rocket motors-some questions

[Abdullah]

I've been firmly told to start rocketry with solids. I have some questions.
1)how do you do casing cooling?
2)how to make sure fuel burns at rate casing can withstand?
3)can rocket candy be made by mixing ground oxidiser with already molten sugar?
4)is using an empty gas cylinder as a casing a good idea?
5)how does rocket candy react to water and seawater?
6)how can nozzles be made?
7)what should I expect from thermal expansion problems?

 

[mahdavi3d]

One hour long DIY solid rocket engine goodness :

 

[Urwumpe]

I've been firmly told to start rocketry with solids. I have some questions.
1)how do you do casing cooling?
2)how to make sure fuel burns at rate casing can withstand?
3)can rocket candy be made by mixing ground oxidiser with already molten sugar?
4)is using an empty gas cylinder as a casing a good idea?
5)how does rocket candy react to water and seawater?
6)how can nozzles be made?
7)what should I expect from thermal expansion problems?

1) You don't. You usually have a layer of insulation between case and fuel, that absorbs heat while charring. The burn time is too short to significantly heat the massive case.
2) By using the right mixture. Good rocket propellants decrease in burn rate, when pressure increases. Bad ones explode.
3) Maybe.
4) Some people do that. But could be a bit large for small scale rocketry. Also the weak spot is the throat, not the case.
5) If you are not storing the fuel there, it should be fine.
6) Ceramics are a good option
7) Less trouble than from increasing the pressure inside the vessel = inflating it.

 

[mahdavi3d]

 

[mahdavi3d]