I was wondering...

[Star explorer]

well i was wondering about those multiple stage model rockets. i understand how to ignite a one stage rocket but how does a lets say 3 stage rocket work. how do the 2 and 3 stages ignite

 

[Quick_Nick]

well i was wondering about those multiple stage model rockets. i understand how to ignite a one stage rocket but how does a lets say 3 stage rocket work. how do the 2 and 3 stages ignite

I'm guessing that the seperation 'charge' at the end of the first motor ignites the next motor, but I've personally never used multistage rockets.

 

[Star explorer]

well maybe but i would like to get an answer to someone who used them before

 

[Deke]

I'm guessing that the seperation 'charge' at the end of the first motor ignites the next motor, but I've personally never used multistage rockets.

I've done some in the past, that's basically how it's done. Basically.

 

[Torgo]

I'm guessing that the seperation 'charge' at the end of the first motor ignites the next motor, but I've personally never used multistage rockets.

I'll confirm... the lower stage engines are specially designed for multi-stage use, so that their ejection charge instead (hopefully) ignites the stage above it.

 

[RocketMan_Len]

I'll confirm... the lower stage engines are specially designed for multi-stage use, so that their ejection charge instead (hopefully) ignites the stage above it.

I'm going to assume you're talking about Estes-type motors, because anything larger than an E requires something a little more complex...

Booster-stage motors do not have an ejection charge built into them. The motor simply burns until a hole develops in the top end. The hot gases then ignite the motor above it - generating (hopefully!) enough force on the lower stage to push it away from the rest of the rocket.

Using this technique, you can add as many stages as you like... although for safety and stability, most designs stop at three stages.

Booster-stage motors are designated by a '-0' as the delay time, instead of the more typical '-3', '-5', etc. Example - a D6-0 motor would be for a lower stage, while a D6-4 would be for the main stage.

 

[Arrowstar]

In high powered rockets, a flight computer is required to ignite an upper stage typically. Most flight computers can handle two stages no problem, and I imagine something high-end could do three. Of course, since high powered rockets tend to fly considerably higher than Estes rockets, if you want the rocket back, it's best to cap it at two... finding it can be hard enough with one motor, much less three!

 

[RocketMan_Len]

In high powered rockets, a flight computer is required to ignite an upper stage typically. Most flight computers can handle two stages no problem, and I imagine something high-end could do three.

I actually *have* a flight computer that can handle two extra igniter channels for staging, and they can be activated by a timer, or by first- or second-stage burnout. I have a setup that can handle two stages, but I'm still trying to figure out how to handle a third... given that all the stages have to be self-contained so that they can be safely recovered. (The big question is the placement of the electronics... :hmm