Flying Fountain (New Firework - It works!)

[usapyro]

At least I have never seen one of these before ever... It's a stable flying firework design I am working on. No propellers, no sticks... Just a rocket engine with a very unique nozzle setup. Unlike a Stinger or Z-Bom it will be highly stable... Able to just set on the ground and launch reliably. Also, this design doesn't lose stability with increased length. I shall have a better video up later tomorrow of one that doesn't blow a gasket. I had a different fuel rammed in midway.

 

http://www.youtube.com/watch?v=xonFRVHixpo

 

It appears it has excellent stability and far more than enough rotation speed. I am going to lower the thrust angle to fifty degrees downward from horizontal to give it a ton more power in the next test which will reduce rotation speed a bit. I will also add some charcoal or FeTi for effect. The nozzles were actually only pointed 20 degrees downward from horizontal even though it appears like more.

 

The final design will be fueled by a fast fountain mix. I should have the finished optimized version done and flying high this weekend! This design might just be stable enough to be able to nearly hover... The nozzles are offset off center to create the spin. This was all inspired by the flying hummer incident > http://www.amateurpyro.com/forums/topic/7862-modified-hummer-design-w-video/

 

As you can see, the lower internal area of the nozzle's are going to erode fast, but that doesn't matter as long as there is still plenty left to steer the gas properly. The middle drilled section can be expanded a bit more to allow you to offset the nozzles more for more efficient rotation with more thrust. I just don't have the right drillbit at the moment!

http://i49.tinypic.com/2vjsacw.png

 

Ever seen a header blowout accelerate a rocket in the direction of travel? Whats kinda funny when you watch the video is you can still hear it rotating even after the header blowout. Really confused me at the time.

http://i45.tinypic.com/2jdg8c6.jpg

Edited October 27, 2012 by usapyro

[PyroAce]

Nice work! I'm loving these experiments of yours usapyro. I will have to have a shot at making these, the flight path is quite stable, when I first saw the device I wondered if it would be an erratic flight path.

I'm going to use a Potassium Nitrate/Charcoal/Meal Powder/Aluminium formula for some spinners, let me know what formula you end up using.

[usapyro]

Yea, the rotation speed on that one was ridiculous... I am half suspicious it rotated so fast it cracked the grain! Jk, but far more rotation than required! Remember this... The more offset you can put the nozzles the better the rotation stability. The more angled the nozzles the less rotation stability and the more forward thrust. The happy balance is likely around fifty degrees. That dedicates most energy to thrust but still has enough going to rotation and pushing sparks outward.

 

For an extra straight launch you can probably launch them out of a short tube that is half the length of the rocket. Shouldn't be needed though. There is a trick to the stable launch. Ram a delay fuel inside the internal nozzle so there is no thrust before it hits the main grain. If you put a fast fuel in the internal nozzle area it might tip it over.

 

Also, one little thing to help you with the nozzles... They are actually longer than my side view drawing makes them appear. This top view give you a better idea. I intersect the side of the internal nozzle with the exit nozzles. I also have some makeshift tooling I created for ease in making these. A large drillbit with a depth stopper and a tool for drilling the nozzles perfectly.

http://i48.tinypic.com/20hvtk6.jpg

Here is a better side view...

http://i46.tinypic.com/4icu8m.png

 

Once this design is tuned I am going to mess with this one a little... The only problem with this modification is there is no place to put an effect ending...

http://i50.tinypic.com/ac52j4.png

Edited October 27, 2012 by usapyro

[superspike23]

great idea these flying fountain.

 

it looks like a little helicopter fireworks.

 

http://youtu.be/QU7VjzGySkc

[usapyro]

Thanks! I never had much luck with those little helicopters... Too finicky and unstable in my experience.

 

Oh, here is a picture of my final wooden tooling. Should help those that are trying to make these. This works nicely! I press the V section straight down onto the tube very hard when drilling through to make sure the alignment is perfect. The end of the small block marks the point where the drill bit tips will meet inside the tube. Those wooden rounds are made from the same dowel size as I roll the tubes. I used a file with the drill on to smooth them off and round the edges.

http://i48.tinypic.com/2416m3q.jpg

Edited October 27, 2012 by usapyro

[AirCowPeacock]

Interesting how you made the tooling. For alot of the rocket designs youve posted on this site Ive been wondering how you manage to tool them; this one in particular. I probably would have disgned this tooling rather differently--but yours is much simpler and as such better for prodotyping. It perhaps takes less time too. As for an effect ending, perhaps placing it on the top with some well timed fuse would do the trick, placed on the bottom it could perhaps be damaged by the rocket exaust. Have any ideas for a diverging portion on that rocket?

[usapyro]

Diverging portion? Not sure what you mean... The jets fire the gasses away from the rocket. The casing below the nozzles is totally unburned but a little dirty.

 

New video...

http://www.youtube.com/watch?v=SkhE13H5Zd8

"The final design is finished!!! I got the angle nozzles where I like them and the launch system works nicely. It's amazing how straight these fly... Wow... 4% blended willow charcoal was added to the fuel to give it a little bit of a tail.

 

From here on it's just tweaks with different fountain effect fuels, burn rates, and etc...

 

My bottom header blew out again and accelerated the rocket upward late in flight. I thought I rammed it in hard enough this time... Oh well, that is an easy fix."

 

 

The first effect fuel I am going to try is two increments of fast 50:50 BP/SF + 5% ball milled pine charcoal to get it off the ground and spinning... Then a switch up to a slow +5% blended pine charcoal + 8% FeTi with 50:50 BP/SF for a couple increments... Then back to fast fuel, then ending with +12% FeTi followed by a flash header. LoL... This thing is going to spread a MASSIVE inverted FeTi cone... Going to use pretty large mesh! Maybe toss in a little rough MgAl... Maybe extend the length two inches for better viewing time! Maybe not needed once I start using slower effect fuels... We shall see! I am not interested in this thing going to high. It's supposed to stay within easy viewing distance as it's a "Flying Fountain". The height in this video was like twice what I want.

 

50:50 BP/SF = Black Powder Meal/Sugar Fuel (66/34/+2 - Powder) for those curious about my fuel mix. I am still using starched confectioners sugar... Going to switch to proper sugar once I go into town tomorrow or the next day.

 

 

Beautiful... Except for that goddamn header... I have YET to not have the bottom header blow out on one of these. About to hot glue it in... LoL! I guess one teaspoon of bentonite for the header isn't enough...

http://i48.tinypic.com/e05sib.jpg

Edited October 28, 2012 by usapyro

[AirCowPeacock]

I mean your 'rocket nozzels' have no diverging portion, theyre just holes in the casing. Obviously it works, but your losing alot of thrust this way--your exit gasses are under-expanded.

[AirCowPeacock]

I'm not so sure your slow fule is going to be much slower than your fast fuel.

[usapyro]

Effect ending... I was just really referring to some stars being shot downward out of the downward header or flash.

 

Hmmm... How much charcoal do you recommend I add to slow it down? Lol... I can only add so much rough charcoal before there is ramming issues... Will an additional +10% ball milled pine slow it down enough in your opinion? I could always switch down to BP:SF 30/70 or so I guess... What it comes down to is figuring out the ratio of effect... (Pine Charcoal, FeTi, MgAl, etc...) added to the fuel vs the fuel speed ratios I use. This is the magic of starting off with my 50:50 BP/SF base fuel. I can keep it going the same speed by shifting the ratios toward more BP as I add elements for effect, or I can slow it down even more by going the other way.

 

I like your nozzle recommendation. I will use one of my V shaped drill bits to give it nozzles. Those things work wonders for us "improvisers" who don't like to be constrained by sets of tooling. Little bit tricky to align those nozzles properly in this case... Hmmm... It's probably not too important though. This thing will fly straight with one nozzle when it's spinning. I wonder if it's got enough gyroscopic stability to do a short hover without changing direction?!? Probably need a perfectly straight up metal tube launch...

 

Random Idea: Would be funny to have one of these things lift a stinger as an "underneath" second stage... The separation could be done smoothly. Just have to accelerate the first stage forward out of the way as the stinger below ignites with some thin sticky match.

Edited October 28, 2012 by usapyro

[AirCowPeacock]

Yeah I was thinking you could switch your BP:SF ratio for the slow burn. Not that you neccicarily need to change the burn rate atall. With a stinger on the bottom the way I think your talking about I would be concerned about changing the orientation of the stinger..but then again--the stinger would already be spinning pretty good. I'd like to see a two stage fling fountain. Im interested in how much Higher these things get with a decent CD nozzle. For a good compairison keep the throat size the same, to fight errosion give the throat a little length, this could be achived by drilling the diverging potion after the throat was drilled with a straight drillbit, leaving a little of the straight portion there. It will be important to keep both sides divergences even. Curious to see what this concept blooms into--it could be big in a few years.

[usapyro]

Yea, it's an extremely safe predictable flying firework design. No unstable flight characteristics and bullet accuracy trajectory. It's kinda like an easy Girandola!

 

I just realized something... If you listen carefully with the volume up you can hear a gravel sound before launch. It launched at the exact trajectory it was aimed at, but the damn thing had moved because my delay fuel was a little too hot... In post analysis when I recovered it one of the nozzles was drilled slightly off getting less gas flow. I still have the nozzle setup fully intact for analysis if you want a picture of how they look after burn.

 

There actually isn't any nozzle erosion internally surprisingly...

 

 

One other thing I still wonder... How much fuel loss am I getting on those bulkhead failures? Look a the images in those frames... See the small dark spot when the bulkhead goes? Mix of clay and unburned fuel? I wonder... Lol... I have never had bulkhead failures like this before... The first one was a 3/4th loss of fuel on bulkhead failure. This one might have still been around 1/3rd... Not really sure! The reason is because the inside of my tubes are aluminum tape. Things slide and compress very easily... But, they blow out instantly without a clay header. I omit the aluminum tape from the nozzle end for a strong grip of the plug vs paper, but it looks like I have to do the same for the other end with these!

 

I will probably also hot glue behind the clay bulkhead against the paper too... *I meant bulkhead before, not header... Argh... Was using the wrong word for ages!* Tired of constant bulkhead failures!!!

Edited October 28, 2012 by usapyro

[AirCowPeacock]

Well if you have that nozzel a sharp point I'm sure you'll get crazy errosion, unless perhaps your using high quality nozzel mix w/ grog and alot of pressure. What's the ID of the tube your using for these?

[usapyro]

1" I.D. I pretty much always make rockets the same I.D. and vary my lengths. The effective fuel grain on that rocket is only approx 2.25-2.5 inches long. By increasing the length two inches I can double the flight time.

 

No inside erosion and very little outside erosion. The reason is because the paper takes so long to burn away it leaves little time for the outside of the nozzle to erode. There is kind of a 0.5 to 1mm buildup of sugar/starch on the inside nozzle areas... Stupid confectioners sugar additives might be to blame! I don't recall sugar fuel being very drossy before...

[shagaKahn]

Ever tried sorbitol for the fuel? Have found it much less messy than straight sugar.

[usapyro]

Never had any luck getting any sorbitol... I ordered from this one place... They didn't send it for a few weeks then the order expired without charging my card. They didn't have it anymore or something? Was through a amazon sellers store. The only other place I found it was a restaurant supply that only sells 50lb bags.

 

Ugh... Gave up on it! I was kinda interested in some mixed sorbitol/sugar grains. Taking advantage of sorbitols low melting point to use it more like a melt cast binder for the sugar in the composition. Why not pure sorbitol? Too much grain shrinkage issues!

[shagaKahn]

Too many bad experiences with candy fuel rockets discouraged me for many years--but I got back into it with sorbitol. Like the fact that I can mix the ingredients dry and ram them using my existing BP rocket tooling.

 

Honestly ain't tried straight sugar since I scored some sorbitol, so I can't speak for its being better or worse than sorbitol; maybe just for comparison sake I'll try dry-ramming some candy rockets using straight confectioner's (prob'ly go for powdered) sugar.

 

Oh and you can get sorbitol from Skylighter. At 14 bux a pound it's surely more precious than regular sugar; think I must have scored mine in some kind of package deal.

[usapyro]

Ugh, ill just stick with normal sugar. Works fine for me! Bought a 10lb sack of fine granulated for like six bucks in Safeway today... Just needs a little ball milling!

 

Test Three... Shot it into/through a fog bank accidentally it looks like... At least I think that is what was going on! I also might have forgotten to put charcoal in my 30/70 BP:SF increments or something... Damn thing disappeared on me! I launched with a couple 50/50 increments (+4% willow charcoal, not pine) then switched down to the 30/70. Fog is everywhere tonight with this rainstorm blowing through! Need to add a bunch of pine charcoal to my fuel so these things are more visible! Was in a rush tonight.

 

http://www.youtube.com/watch?v=avQyOJ8MCNo

 

See how that fog far above appears bright and that fog just it above appears dark... I am pretty sure that means there was fog between the camera and the report... Probably just layers of fog everywhere! That FeTi was way too dim for that distance...

 

http://i46.tinypic.com/35k2a2p.jpg

Edited October 29, 2012 by usapyro

[AirCowPeacock]

Where was the salute attached? Was it in the tube?

[usapyro]

The normal way... Taped behind the bulkhead on the header!

 

http://i48.tinypic.com/261lr7l.png

[AirCowPeacock]

You do love your MS Paint, don't you. (;

[usapyro]

Actually I am using photoshop CS5. It's real tricky to replicate a spray with with brushes.

 

I am going to angle the internal nozzle area better and lower the rotation speed on these things...

 

I am suspicious the rotation speed is acting like a vortex vacuum cleaner and holding charcoal/metal particles against the sides of the rocket internally and preventing a lot of them from exiting the top nozzles as much as they would normally.

Edited October 29, 2012 by usapyro

[AirCowPeacock]

Not to mention the effects from errosive burning. Ive been thinking, if you drill a divergence on the nozzle..well, it wouldnt be even. I wonder what effect this would have, and whether or not it should be corrected. I would think it could push more force to the sides causing more spin, but perhaps not. I would like to see this thing at maximum performance; wouldnt you?

[usapyro]

Not to mention the effects from errosive burning. Ive been thinking, if you drill a divergence on the nozzle..well, it wouldnt be even. I wonder what effect this would have, and whether or not it should be corrected. I would think it could push more force to the sides causing more spin, but perhaps not. I would like to see this thing at maximum performance; wouldnt you?

 

I am not going for height. I just want stability and flight time so that I can have great visual effects while in flight.

 

If your interested in high performance as in... A lot of height! What you will want is a very small offset. Just enough so that you have stable rotation. You will also want to try for as low of a nozzle angle as practical... Somewhere around 60-70 degrees probably.

 

I may eventually test some designs with low offset and very low sloped nozzles that can knock out some serious vertical, but that isn't my focus right now. Those low sloped nozzles need a pretty long plug, but it can be very thin so the weight is minimized!

 

 

I like these 50 degree vents with 7mm offsets, but I am probably going to settle for something at like 50 degrees with a 5mm offset. Not much rotation speed is really necessary for a stable flight in a puller motor. If I decide I want to throw more Charcoal/FeTi/MgAl in the air with a wider spread I may go back to around 35 degrees. Your choices in vent angle really just depend upon what you want to do... I want something that flies slowly and tops out at 75-100' and has good stability. That is my goal!

 

In the next couple days I will get a video up of one of these launched with 10-15% pine charcoal of different mesh sizes. Superfine stuff is ball milling right now!

Edited October 30, 2012 by usapyro

[usapyro]

For those trying to make their own tooling for creating these... Here is the updated aesthetically pleasing optimal design.

 

http://i46.tinypic.com/4v4owz.png

 

Key points...

1. The angles on the tip and choke point of the internal nozzle must be the same as the vent nozzle angles you decide upon... Be it 45 degrees, 30 degrees, etc... Why? Reduction of the amount of weight of clay, keeping strength symmetrical, and etc...

2. The internal nozzle must be at or slightly over half of the tube I.D. in width. So for a I.D. of 20... That would be 10. Why? Again, reduction in weight of clay, and allowing for smooth unrestricted gas flow to the nozzles.

 

Here is a top cutout view. The green lines on the left indicate the cutout area I am showing on the right. The vent nozzles usually don't cross each other. They are offset to generate rotation. The amount of offset is your own choice. More side offset = more rotation torque = faster rotation speed = more perfectly straight flight. If your skilled enough you can probably get a stable flight with as low as 2mm total vent nozzle offset on a 1" I.D. rocket! LoL... The rockets in my videos so far have been max offset to the point ONLY HALF of the drillbit actually goes through the delay composition I ram into the internal nozzle. I recently realized this much offset was totally unnecessary.

http://i45.tinypic.com/5d3spi.png

As for nozzle vent sizes... I think I am currently using 4mm with a 1" I.D. when I use my 50:50 BP/SF fuel. Not 100% sure about that 4mm. Have to go check... It isn't important. Just adjust your vent nozzle sizes properly to whatever fuel you choose to use. And, for those who have not made stingers or spinning rockets before... Those vent nozzles are drilled last!

 

You can use whatever vent angles you want from a range of 35 degrees downward to like 60-70 or so. I have tested from 20 degrees to 45(I thought it was 50, but I just re-checked and my angle on my current improvised tooling is 45). If you want to go for serious height go for a real low vent nozzle angle like 60-70. It gets to be a real pain in the neck to drill at those kind of angles though. I have gotten off the ground with nozzles only angled 20 degrees down(first video)... But you need a hot fuel and high pressure to lift off... No reason to use an angle that small.

 

Tip: If your launching these in a location where stuff can be damaged by falling objects... I would recommend putting in enough flash behind the bulkhead to shred the thing! These things have quite a bit of clay weight in them and fall like a rock. On the plus side, if you launch straight up to a height of around 150' it usually only falls within twenty feet of the launch point. The flight path on these things is ridiculously stable...

Edited October 30, 2012 by usapyro