Nozzleless Rockets

[Bensmith]

I've been goofing around with nozzleless motors for a bit. I've gotten quite addicted to the performance, ease of manufacture and reliability of these motors. Great performance with hot BP or benzoate whistle fuel. Plus, with a taller spindle, strobe rockets have a bit more "pop" to them. Here's a pic of the tool set I ended up developing. Additional details are on my site

 

-Ben

 

 

Setting Other People's Lawns on Fire for Over 30 Years - www.firesmithtools.com

Edited December 18, 2012 by Bensmith

[Oinikis]

very nice tooling! i'm making rcandy nozleless rockets, using my homemade rocket tooling whitch is a simply a plank, with several nails stiking out, acting as a core former, and several diferent sizes homemade wooden dowels with holes, but works ok for me. actualy nozzled rockets are more powerfull, using same amount of fuel, gives out more power, becouse outgoing particles speed is greater, but nozleless rockets are much easyier to make, and i make them becouse i can't deal with shooting plug dillema, becouse for it to work i need very big plug, but these rockets are very nice, and are still good for lifting. congratulations for having such a nice tooling, where did you get it?

[Bensmith]

About the only time I make nozzled (or choked) rockets anymore is when I'm wanting a quiet "woosh" from a BP motor. However, with as much fun as whistle rockets are (and the fact that they put out a tremendous amount of power) I've gotten away from making nozzled rockets. The toolset mentioned above is my design for pyros who build allot of nozzleless motors. Checkout my website if you get a chance. I design and manufacture about 150 different tools and machines for pyro use. My stuff is being used in the US and another 12-14 countries throughout the world.

 

-Ben

 

http://www.firesmithtools.com

[WonderBoy]

What is the difference between this and the Super BP spindle, besides lack of much convergence/divergence? Is it skinnier? Longer?

 

 

WB

[californiapyro]

it looks longer. I have been thinking about doing something like this, using a longer and longer spindle to see how much I could really get out of nozzleless BP. come to think of it, the divergence really isn't important for these, smart doing away with that.

[Oinikis]

it's probably very nice to use such a tooling, and you said, 14 countries around the world, i bet there is no Lithuania in that list

[Bensmith]

This spindle is a bit taller and skinnier than the Super BP. Plus, without the convergent/divergent tapers, even with a tall spindle, I am able to leave a big chunk of space at the top of the tube for delay and effect.

 

Oh... yeah... no Lithuania as of yet ;-)

[Algenco]

it's probably very nice to use such a tooling, and you said, 14 countries around the world, i bet there is no Lithuania in that list

 

you could be the first

[Oinikis]

actualy i do not make much rockets, but when i do, i use my homemade tooling.

[PyroCube]

Hi all

 

I made my first nozzleless rocket with 75/15/10 CIA BP, but it exploded right away, not a plop or something like this,

it was a real explosion, like 3g of flash powder.

 

After this I tried with 68/22/10 BP, just screened together. This worked fine, altough my fuel was quite weak, it went up extremely fast, quite a surprise

(I used a 15mm ID Tube, Core lenght was about 8cm.)

 

But now I want to lift some 3" shells with this motor, so I planned to go up to fast 75/15/10 BP again. (This time ballmilled)

Has anyone a method to be sure it doesn`t CATO? I bought some mineral oil (Called lamp oil here in switzerland) recently, can I add

just about 3% to my fuel? I suppose it`s quite difficult to distribute such a small amount in my BP, maybe it`s better to thin it a bit?

Unfortunately I haven`t got laquer thinner here, is there an other choice, something like acetone?

 

Thank you,

Greets

[nater]

Why not just water? Get the mill dust damp, granulate and dry.

 

Are you pressing or ramming the motors?

[PyroCube]

I`m ramming my motors.

I don`t think that mineral oil is dissolving in water,

or is the mineral oil unneeded?

[a_bab]

Your core length is fine for the size of your rocket.

Causes for BP nozzleless CATO (can be extended to whistles):

-hot too fuel (this relates to too long of a spindle)

-crack in the fuel

-weak tube (what kind of tube did you use?)

-weakened tube (cracked internally, paper fibers broken - you can't see this but it will cato)

-weak end plug - you need at least 1.5xtube diameter

 

I'd suspect the tube in your case.

 

Specs for a working nozzleless rocket in my experience:

 

Tube diam: 18 mm

Spindle specs:

lenght: 75 mm

base thickness: 7 mm (8 works)

top diam: 6 mm

1 rammer, 7.5 mm hole

fuel: ballmilled BP, willow charcoal

It can carry 300g with no problems.

[PyroCube]

Do you treat your BP with something or do you just press it in out of the ballmill?

I tried another 15mm nozzleless motor with 75/15/10 BP and 4% Mineral Oil.

It went straight up with a strange noise, but not as high as I was expecting.(120g dummy header)

Maybe using lamp oil isn`t a good idea?

 

http://www.youtube.com/watch?v=lrHFZfHzAuU&feature=youtu.be

 

Last time it exploded, I was using these tubes:

http://www.oliverbrown.co.uk/acatalog/100mm_x_15mm_Cardboard_Tubes.html

I dont think the fault was in the tubes, maybe my little granules of CIA BP were a bit too strong, and

the fuel grain had little air bubbles in it.

 

Greets

[Col]

The strange noise is called "chuffing", reduce the mineral oil to make the fuel a little hotter

If the 15mm tubes are anything like the 1lb rocket tubes, they`ll be spiral wound and not much use for rockets.

Edited February 9, 2013 by Col

[AlexPyro66]

Do you treat your BP with something or do you just press it in out of the ballmill?

I tried another 15mm nozzleless motor with 75/15/10 BP and 4% Mineral Oil.

It went straight up with a strange noise, but not as high as I was expecting.(120g dummy header)

Maybe using lamp oil isn`t a good idea?

 

http://www.youtube.com/watch?v=lrHFZfHzAuU&feature=youtu.be

 

Last time it exploded, I was using these tubes:

http://www.oliverbro...oard_Tubes.html

I dont think the fault was in the tubes, maybe my little granules of CIA BP were a bit too strong, and

the fuel grain had little air bubbles in it.

 

Greets

General the nozzleless rockets will travel lower than the rockets with nozzle but will lift bigger weights for a short period of time.And something else your rocket stick seems to thick what diameter does it has

[PyroCube]

I know it`s a bit thick but it was the only one laying aroung, so I took it.

I think that shouldn`t affect the rocket performance...

Maybe I shouldn`t use mineral oil at all, I suppose the rocket would have gone much higher without...

 

 

Greets

Edited February 9, 2013 by PyroCube

[psyco_1322]

You can use mineral oil to help slow the fuel a bit and keep the dust down. Given that 4% made it start chuffing, I would go with about 2%, it shouldn't take that much of the performance away. To mix in the oil, you can add it with the bp in a bag and knead it with your hands for a while, then run it through a screen 3 or 4 times, this really gets it well mixed in. No solvent is needed for the oil.

 

One thing about hand ramming rockets, is that using fuel that had hard granules usually will cause issues. It's hard to compact hard granules into a solid, steady burning, fuel grain. If un milled powder makes the motor blow, milled powder will probably make the issue worse. What Nater was suggesting was to granulate it with just water, and not use a binder, this often makes soft granules that can be rammed. You can do the same with alcohol if you want.

 

Another thing that helps, get a bigger hammer. Rubber mallets are pretty bad for consolidating fuel, a dead blow is better for the task. Give each increment about 10 good and hard blows. If you see the tube bulging really bad, ease up on the hitting force. Also make sure the height of your increments are only 1/2 - 3/4 the ID of the tube after you ram them.

 

Try to make sure to light the end of the fuel grain, don't stick the fuse up inside the core. Sometimes that can make a world of a difference.

[Mia]

The strange noise is called "chuffing", reduce the mineral oil to make the fuel a little hotter

If the 15mm tubes are anything like the 1lb rocket tubes, they`ll be spiral wound and not much use for rockets.

Convolute wound, 3mm wall thickness.

[Scrumpy]

The strange noise is called "chuffing", reduce the mineral oil to make the fuel a little hotter

If the 15mm tubes are anything like the 1lb rocket tubes, they`ll be spiral wound and not much use for rockets.

Colin, what is your obsession in trying to poison against www.oliverbrown.co.uk it happens quite often, you seem to enjoy having a dig whenever possible? Without suppliers the hobby would come to a finish quite quickly for most of us, I don't see you trying to supply people or even add any constructive information, just confusing maths that make little sense.

If you bothered to read the description of the 15mm tubes you would see they are convolute and have a decent wall thickness, ideal for pressed and rammed rockets. You make reference to the 3/4" tubes I sell as being "not much use for rockets" what do you base this on? These tubes are fine for hand rammed rockets, they are cheap and strong enough for what they are used for, I sold close to 10,000 of these last year with no complaints, well other than you and I don't think you have ever bought any, just have a strong opinion.

[Col]

Can only judge by the number of pyro`s having cato issues with the 1lb`ers. As for constructive information, I do try to post pyro hobby related video`s and pics, rockets,wheels, inexpensive homebrew tools that most people could make for next to nothing (the latest was for inserts). I uploaded the newspaper can shell pdf on the off chance it may be useful to others. My latest offering on you tube is a couple of tube supports that anyone can make for a few pounds. I guess we`re on different sides of the pyro hobby as your latest vid was "10mm rocket tooling available to buy at oliverbrown.co.uk"

[Scrumpy]

I love making things for free, and when I have time it's great fun doing so. Not everyone has spare time and quite a lot of people are very happy to pay to be spoon fed, I offer this service, I am a spoon feeder..... I buy and sell all the chemical needed for this hobby so people can easily find them all in one shop, I supply tooling either to my own designs or custom built at a very affordable price as most people can't make such things, I also supply consumables such as headers and tubes, of course these are simple to make but people cant be bothered. It eludes me why you are upset with me, I am serving the UK market and making a pretty good job of it.

I know there is history between you and Mia but there is nothing between myself and you, I know you don't like some of my tubes and I agree the 3/4" are weak but for the masses to fire off a hand rammed rockets in the back garden they are fine, I've never seen one of your tubes in person but they look amazing on screen and I see you take great pride in making them, most people can't be bothered.

You are right, my last vid on youtube was for my 10mm set, this is a great advertising outlet for me, it's free and easy, this is a pocket money set aimed at getting more people interested in this hobby.

I don't think I have upset you but none the less I'd like to offer you a peace offering, how about I send you one of my 10mm sets and some tubes for free and if you choose to review it I will take any critisism on the chin, does that sound fair?