Dual stage rockets

[insutama]

Anyone ever tried making a 2 stage or more rocket ? the idea intrests me i would like to try it. I would think you would just attach the second moter on top of first one and make a small burst at end of engine to ignite second engine. anyone ever tried this ?

[calebkessinger]

You tube it! Lot's of people have done it.. it can get interesting

Short or no delay on first motor, just tape it to the second motor with a tape that can melt, or ask some others how they have done it. The fire from the first motor should light the second just fine. Try not to put too much weight on top, they tend to arch over and can go all kinds of crazy directions when the second motor lights. Yep, you can stack three with no delay, just remember, you could get a visit from your neighbors a mile away if they get crazy..

You got me ready to make some rockets!!!

[carbonhalo]

yep...hard to get 2nd stage to fly straight

[dagabu]

Anyone ever tried making a 2 stage or more rocket ? the idea intrests me i would like to try it. I would think you would just attach the second moter on top of first one and make a small burst at end of engine to ignite second engine. anyone ever tried this ?

 

Dan Thames made this one back in Gillette, just ignore the nice big shell on the other one.

 

http://www.skylighter.com/images/newsletter/113/pgi-mfg-area-03.jpg

Edited February 20, 2015 by dagabu

[MrB]

I know 2-stage rockets are used for "rocketry", but for pyro? The bulk of the weight is the shells, so there isn't much to gain from using a stage, and releasing it. Some people use multiple motors, to lift larger shells, but they mount them next to one and other, rather then one above the other, so to speak.

 

Anyway, a cored second stage can be reliably lit by sticking a short length of black match in to the core, and making sure there is fire from the top of the motor to light it. Nozzle-less with a slight delay makes for most viewing pleasure, in my opinion. But again, thats with rocketry, not pyro, so no idea there. I've mostly used engines with nozzle, making sure i had a good enough fit that the engine stayed in on it's own, but was easy to slide out, with nothing to hold it in place, which means the empty cartridge gets ejected when the second stage lights. Nozzle less, and no bulkhead pretty much always left the "first stage" cartridge remain in the rocket body. This could probably be adjusted by simple drilling in to the delay slightly, just to create a small obstruction when the second stage lights, but as i said, i mostly used engines with nozzle, so it wasn't something i bothered with. At least to me, the whole point of 2 stages (or more) was to eject the empty cartridges, to become lighter, and faster.

But that was a couple of years ago, we were a couple of guys using rockets in a way there weren't intended. Lets just say nobody bothered with parachutes.

B!

[insutama]

interesting guys so much to learn probably wont be making multi stages for awhile.

[mikeee]

I have made a few of these each year, I just use a collar or bushing in between rocket motors

and use a friction fit on the collar so the bottom motor drops off when the second stage ignites.

Attach the rocket stick to the top motor only so the bottom motor falls away after the 2nd stage

ignites and pushes the 1st stage off. A little loose fuel grains on top of the 1st stage helps ignite

the 2nd stage and ejects the 1st stage motor at the same time. I have used BP, whistle and

strobe fuels for these two stage motors.

[max]

But again, thats with rocketry, not pyro

+1

[mikeee]

Add some molecular titanium to your fuel and that Rocketry is now Pyro. :-)

[dagabu]

I have made a few of these each year, I just use a collar or bushing in between rocket motors

and use a friction fit on the collar so the bottom motor drops off when the second stage ignites.

Attach the rocket stick to the top motor only so the bottom motor falls away after the 2nd stage

ignites and pushes the 1st stage off. A little loose fuel grains on top of the 1st stage helps ignite

the 2nd stage and ejects the 1st stage motor at the same time. I have used BP, whistle and

strobe fuels for these two stage motors.

 

Mikeee,

 

Do you use a retardant in the nozzle of the upper stage when using whistle?

[mikeee]

Dave,

 

I have had good luck with pressing the whistle motors as usual and stacking one on the other

without altering the motor/delay etc. You could always J-hook some black match in the 2nd stage

motor to assure ignition, but all of the ones I have assembled ignited when the delay on the 1st motor

burned through and passed fire to the 2nd stage motor. On a few of them I would dump a little loose

BP fuel on top of the 1st stage which would create a small burst charge to eject the 1st stage. I made

several of these 2-stage motors without any BP on top and they also ejected the 1st stage with no

problems, the thrust from the 2nd stage was plenty to push the 1st stage off.

[WonderBoy]

It's been a while since I have made one, but multi stage motors are a lot of fun. It is pretty awesome sending a motor way into the clouds, then having a several second delay from flash to boom. I've also done funky variations like using a Stinger missile as the second stage.

 

Another benefit of using multiple stages is that you can lift heavier shells by using a "booster" motor to get the load off the pad, then once it's in motion it doesn't take as much power to keep it moving. One on my favorite examples of that is a Dan Thames rocket, the description starts at :27 http://pyrodan.privatedata.com/fireworks/pgi2010-dant-rocket-level-4.wmv

 

For attaching the stages, I like to minimize back pressure. So to do that I use two guidance sticks, then cut two 2"ish sticks, and attach them at the bottom of your top motor, extending maybe an inch beyond the bottom. Then your booster motor slides up inside the 4 sticks. Doing it this way, gasses can immediately escape when the top motor ignites vs. having that extra inch of collar or tape or whatever.

 

 

WB

 

[dagabu]

I have had NOTHING but problems with two stage whistle, I cannot light the top if its whistle, they always CATO, I have to light them as a single stage, edge lit with visco.

[WonderBoy]

What types of spindles and comp were you using? I've made quite a few two stage whistles without problem, but I generally don't use a super aggressive motor for the second stage.

 

 

WB

[dagabu]

Just the standard Benni whistle, 70:30:1 stuff.

[WonderBoy]

Dag, what spindle were you using? I consider 70:30:1 whistle to be "slow", not standard whistle.

 

 

WB

[dagabu]

UH set from Steve LaDuke, I fly them with 4-6 increments of 70:30:1.

[ddewees]

To the moon Alice!

[dagabu]

I wish, I really do! I can do dual stage rockets with whistle on the bottom and en end burner on top (talk about height!) but whistle on top always results in a POP!

 

I think that is what Dan did with his two stage in the picture above, I will use three fins and not five like he did though.

Edited February 24, 2015 by dagabu

[Mumbles]

I've seen cplmac do 2 and 3 staged 6lb whistle rockets, so it can be done. Maybe watching some of his videos could lend some insight. All the ones I saw him assemble used a Fe2O3 catalyzed mix, and I believe he was pretty loyal to using Sali whistle. They all had cores as far as I recall, though almost certainly the older type whistle tooling, which had a less aggressive core than some of the stuff available now. All of the multi-stage stuff I witnessed him build used a single stick with the rockets attached with slitted masking tape. To give fire to the next motor he used granular whistle mix and/or a wad of blackmatch.

[dagabu]

I have seen the video but never heard an explanation of the process before. It just blows me away that a multistage whistle can be made without blowing up. Alas, I'll probably never make one but the temptation is there.

[psyco_1322]

I have seen the video but never heard an explanation of the process before. It just blows me away that a multistage whistle can be made without blowing up. Alas, I'll probably never make one but the temptation is there.

 

Try detuning your motors till they can be lit from the top of the core. Then they'll work.

[mikeee]

I usually press my whistle motors around 8000-9000 on the fuel. Most of the time I am able to J-hook the fusing into the core without having cato's. If the fuel is too hot I usually tone it down a bit to reduce the potential cato's, my hearing has suffered enough over the years I don't like unexpected bombs going off on the launch pad.