Can toy rocket engines be used more than once?

Question

Can toy rocket engines be used more than once?

Answer 1

No.

You would need the special machinery (Like Vern Estes' "Mable") to make the solid propellent "slug", and there are only three or four of those machine around.

Part of what makes the engine work is that the slug IS solid.  Just putting new black powder into the tube does not make the slug solid.  The flame can get between the individual "grains" of propellant, causing the propellant to burn too fast, and even explode.

AND, the act of buring usually damages the clay nozzle.  The design of this nozzle is important for proper gas expansion.  With the nozzle damaged, the thrust of the engine is not correct.

AND . . . how are you going to do the delay charge and ejection charge???

There is a class of reloadable model rocket engines made by Aerotek Industries in Las Vegas.  They use a different propellant that is more like space shuttle propellant.  You buy a special re-usable metal tube, and the 'engine' part comes as a slug of propellant, a new nozzle, and a delay charge.  It takes about 10 minutes to re-load an engine in the field.

Due to the nature of these engines, they are avaialble only in E, F, and G engines sizes.

Aerotek Industries also makes "High Powered" rocket engines up to Class 'N' sizes.  These are re-loadable, and they are BE-UU-TI-FUL when they fly. An 'M' class engine can put a 120 pound rocket about 2 miles in the air in about 6 seconds!

But you have to be at least 21 AND you have to have a special Explosive User Permit from the government in order to even order them.  And lost of money!  an 'M' class engine (propellant only, no tube) is about $800 for ONE flight!

Answer 2

Yes AND No

Estes brand as mentioned are 1 shot non reloadable.

There are reloadable engines avaliable made by Aerotech. See link

Answer 3

If you are talking about Estes model rocket engines, then no, they can only be used once (since the chemicals have been combusted).

I imagine you can re-use the outer cardboard tubing and fill it with more propellant, but thats probably more trouble than its worth.