What do you use?

[WindowLicka]

I was wondering what you people who successfully get their rockets where they want them to go, what are you using to launch them from? I'm generally talking about bottle rocket type rockets, not so much parachute/hobby type rockets.

Do you launch out of a bottle or what? Jk:)

What do you use to stabilize your rocket and get it going up consistently? A PVC launch tube? Pepsi bottle? Specially made launch apparatus?

I'd really like to hear what's your way of launching these rockets you spend hours upon hours making.

I'm sure your not going to shoot'em out of a bottle, though you can.

[OldMarine]

I launch my 1 & 3 lb rockets from a pvc pipe that comes within a few inches of the base of the motor.

[dagabu]

I too use PVC pipe, 1" works for most. I like the motor a few inches from pipe but not too far.

[MadMat]

I use a piece of 3/4 EMT (electrical conduit). One thing to note; if your rocket is taking off "slow" you wont get a good straight trajectory using a stick for guidance (as you called them bottle rocket type). It is important for your rocket to have good internal pressure/exhaust gas velocity right from the start. I personally make my Rcandy rockets with a short core (about 15-20% of the grain length) and add RIO. This way my rockets "jump" right off the launch pad and fly very straight.

[dagabu]

I use a piece of 3/4 EMT (electrical conduit). One thing to note; if your rocket is taking off "slow" you wont get a good straight trajectory using a stick for guidance (as you called them bottle rocket type). It is important for your rocket to have good internal pressure/exhaust gas velocity right from the start. I personally make my Rcandy rockets with a short core (about 15-20% of the grain length) and add RIO. This way my rockets "jump" right off the launch pad and fly very straight.

I call BS on that one. I have seen tens of thousands stick rockets launched and as long as they are made and stocked correctly, they will fly true.

 

Fast rockets that jump off the pad almost always bend the stick dramatically (seen in slow motion video) and perhaps straighten.

 

Stiffness, correct length and alignment are the benchmarks.

[AzoMittle]

I've always seen them as something similar to this, but instead of PVC it was metal piping (3/4" EMT sounds about right): http://www.fireworks-forum.org.uk/threads/how-to-build-a-rocket-rack.16059/

 

Here are more designs: http://tinyurl.com/zd88gos

 

I can't find any images/videos but I've also seen it where the rack is made like a large dining table, except the top/flat surface is chicken wire. Small bottle rockets are added by the handful, as one lights it sets off the fuse of the others next to it leading to a chain reaction.

[stix]

I call BS on that one. I have seen tens of thousands stick rockets launched and as long as they are made and stocked correctly, they will fly true.

 

Fast rockets that jump off the pad almost always bend the stick dramatically (seen in slow motion video) and perhaps straighten.

 

Stiffness, correct length and alignment are the benchmarks.

 

I wouldn't call 'intended' BS on that one, but perhaps a basic ignorance and misunderstanding of what's actually going on.

 

I agree with what Dags has pointed out. "Stiffness, correct length and alignment are the benchmarks."

 

Stiffness - the stick, correct length - the stick, alignment - the stick AND careful alignment of the nozzle ('cause you made it well). You can always put some small weight on the end of the stick to counter the center of gravity, but there is no point if your stick is not rigid and not fastened to the body well.

 

Given those requirements (and no wind), then there is no reason why you couldn't configure your rocket to gracefully take off at a rate of 3ft (1mtr) per second with stability. All good providing the center of gravity has been accounted for.

 

In answer to the question: Rockets with a stick, I wouldn't trust a bottle. I use an aluminium or pvc tube to loosely hold the stick as others have mentioned. For built rockets, ie. nose cone, fins etc. I use a launch tower.

[WindowLicka]

I launch my 1 & 3 lb rockets from a pvc pipe that comes within a few inches of the base of the motor.

When you call them 1lb and 3 lb rockets is that because your putting roughly 1 & 3 lbs of fuel in them?

 

 

That link to fireworks uk forum is right on! Thanks a million.

 

I love the way people call others on discrepancies here....

[dagabu]

In response to post #8: There are a lot of answers for this one and some are true to history and some, not so much...

 

I take from Alenander P. Hardt's Pyrotechnics the table from rockets, page 198.

 

Edited June 25, 2016 by dagabu

[stix]

Nice, but that table shows nothing regarding stick length and therefore I find it rather flaccid.

[dagabu]

Nice, but that table shows nothing regarding stick length and therefore I find it rather flaccid.

 

Nor was there any intent to answer any stick length question nor was the OP asking about that. Thanks for your observation though.

[dangerousamateur]

How long do PVC startpipes last for you guys?

Dont they get damaged rather quickly?

 

I just imagine a slow going endburner. Repeated surface melting cant let them last too long.

[dagabu]

At the PGI convention, there are a few replacements of PVC pipes during the week but as you said, they are primarily due to slow starting rockets, even tame BP rockets seem to leave little damage to the tubes.

 

A rough guess would be 100 or more launches of BP and maybe 200+ of fast whistle before there is any significant damage.

 

Oh, 1 CATO will do it to.

[dangerousamateur]

Thanks, I will try it for my next launch ramp. The one I use now consists of rocket motor tubes glued to a stick.

The tubes hold up pretty well... Only they stink bad.

 

 

 

Oh, 1 CATO will do it to.

A little distance between starttube and motor with shell would cure this problem

Edited June 26, 2016 by dangerousamateur

[dagabu]

Thanks, I will try it for my next launch ramp. The one I use now consists of rocket motor tubes glued to a stick.

The tubes hold up pretty well... Only they stink bad.

 

 

A little distance between starttube and motor with shell would cure this problem

 

That was kind of an inside poke at a member here, 12" ball shell took out the entire rack and a couple others. It was amazing!

[FlaMtnBkr]

PVC, metal conduit, or a 2x4 with holes drilled in it that has legs on either end.

 

For small whistling bottle rockets I've pulled the fuse and little piece of paper out of a bunch. Then put BP in a small cardboard consumer mortar and load the bottle rockets in. The BP lifts them while simultaneously lighting them and they all take off skyward. Something different.

[carbonhalo]

I use the stand off a pedestal fan.

I used to use bottles with a few inches of water to stabilise them, and was surprised to see that a PE milk bottle would last so much longer than a polycarbonate soda bottle.

 

My sticks are usually bamboo, and are rarely straight. I find they don't affect the launch much as long as the centre of balance is below the nozzle.The thinnest can be quite flexible, and whip will sometimes have them wriggle like a fish as they fly. Sometimes they will spin. This probably reduces their maximum height, but makes them much prettier .

[yoyo]

I use a PVC platform, made with 3/4-inch PVC, as you can see here: https://www.dropbox.com/s/a5rs2vj5vvv6u82/MVI_5536.AVI?dl=0

 

There are two vertical pipes for launching. The downside of this method is that a significant part of the r-candy exhaust is steam, which causes the upper portion of the tripod to become moist and dirty. Additionally, over time the PVC may warp from heat, or if the rocket doesn't lift off the pad the pipe will even melt or warp beyond use.

 

Alternatively you could use a vertical wooden platform with several screw eyes to keep the stick and rocket vertical.

[MadMat]

I call BS on that one. I have seen tens of thousands stick rockets launched and as long as they are made and stocked correctly, they will fly true.

 

Fast rockets that jump off the pad almost always bend the stick dramatically (seen in slow motion video) and perhaps straighten.

 

Stiffness, correct length and alignment are the benchmarks.

No intended BS on that. I was just going off my own observations from experiences I have had with rockets. Any rockets I have made in the past have always flown in an arc (sometimes a bad one) when they launch too slowly.

[WindowLicka]

I noticed my cored rockets seemed to explode right after the initial burst of thrust, just about a foot into takeoff. Now my 1st suspect is my spindle size..

What's the normal min - max size for 3/4" x 4" rocket?

 

I mean, doesn't the the spindle shape determine the thrust the rocket will produce?

 

I haven't really shaped it to much just a light taper to the blunt point. But the two rockets both did identicle kabooms.

 

Is this what you call a CATO? What does CATO stand for anyways? Catastrophic failure?

Edited June 27, 2016 by WindowLicka

[dagabu]

There is much argument as to the actual words but basically, it means:

Catastrophe At Take Off, yes, you are experiencing a Cato.

 

Here is a sketch of a traditional one pound rocket tool set.

 

[Redrocketman]

Catastrophe after take off. My bottle rocket launcher is simply a 5 foot length of fence paling with 6 lengths of 3/4 pvc fixed evenly spaced. Two steel droppers screwed in at each end, then the whole thing is driven into the ground firmly. Add 5 or 6 rockets in each one, & run a butane torch across them all. Lauches about 25 in 5 - 10 secs. Not perfect, but does the job.