Black Powder Rockets

[dragonman586]

BBQ C???? You wouldn't mean charcoal briquittes now would you? Because if you do I now have something to try for the weekend.

[brainfever]

No, I mean regular BBQ charchoal pieces.

I don't know the type of wood, but it's not all that soft ...

 

BTW, I pressed these rockets (or rarther, my girlfriend did) on my 15 ton press, the one pictured on my site.

Obviously not to full capacity, just untill the PVC tube exands where the nozzle is situated to give it extra strenght there.

The grain and end-plug is pressed just enough to compact it good, but not hard enough to deform the tube.

[FrankRizzo]

Dragon, think lump charcoal (ex. Cowboy brand)

 

On a similar note, here's a humorous comment from Lloyd S. on the use of Kingsford in willow comp:

 

"I've had similar success by substituting about half the charcoal in a 'standard' willow mix with ground Kingsford. Like you, I assume that the clay, rocks, binders, and bear turds in the Kingsford help make lasting sparks. "

[ewest]

Wait, you get your girlfriend to press your rockets? LOL, I was looking for a good way to make a blast shield for my press, I guess putting my girlfriend in front of me would work just as well.

[Givat]

Weird thing the wrong diamentions of passfire 1/2" rocket.

 

Yesterday I found on UKrocketry forum this picture (I can't remember who made it, but thank you)

http://img98.imageshack.us/img98/3226/05spindle27og.th.jpg

 

I calculated the spindle face area.

Then I calculated how long would be a cylindrical spindle with 4.5 m"m diameter with the "bought tools spindle face area"/1.5 (My nozzle is 1.5 times smaller than this one so I need 1.5 times less face area I guess[because smaller nozzle can handle less thrust])

 

The spindle I calculated is roughly 5 times the ID of my 1/2" rocket - 6 c"m long.

 

I broke the epoxy who holds the spindle in my tools and will try to replace it with 6 c"m long one.

 

hope I will get much powerfull rocket with no cato.

 

 

Any enlightenments and corrections will be accepted happily.

[Bug_X]

I have tryd some BP rocket and all CATO:s or does not lift (2 have lift but faild in some diffrent way)

 

My tubes are homemade and the messure are this

90 mm long

Id 12,7mm (12mm - 13mm)

5 mm thick and the glue is PVA.

 

My first rockets had a ID of 25 mm and then I was recomended to start smaller so I did.

 

I had tryd very many diffrent sizes on the nozzel and core (the nozzel is 12mm - 15mm long in and made from bentonit).

 

This is the messure I had tryd.

Nozzel core and what happend

4mm, 10mm, Fountains

3,5mm, 10mm, had good start but lost all thrus, about 8m upp

3,3mm, 10mm, CATO

3,5mm, 10mm, CATO

3,5mm, 10mm, Lost the nozzel but lifted a 2-3m

3,3mm, 10mm, CATO

3,5mm, 5mm, Fountains

3,5mm, 10mm, CATO

3,5mm, 7,5mm, Fountains

3,3mm, 2,5mm, Fountains

3mm, 2,5mm, lifted 0,7m and then back to ground

2,5mm, 2,5mm,CATO

3mm, 4mm, CATO

 

With the 3 first i used a some lose bp in the core like a primer but stopped with this (I did think i had some with my CATO:s to do).

 

The BP i use is standard BP (75:15:10, KNO3:C:S)

 

And the Carbon is not very good but okey i think (it is made out from BBQ carbon).

 

Sometimes when it CATO:s and i found the rest of the tube, not all the BP have burnd, I think i rammed the bp hard enught, if i open the tube i can use the bp to writte on the wall if i want to.

 

Please HELP ME, what is wrong???

 

/ bug (and my writtning is not very good but please, don´t complane to mutch)

[Pyrohawk]

How did you make your BP? What formula do you use, do you ball mill it, etc..

[Mumbles]

I have a few questions, and then I think I can help you with your problem.

 

First off, are you ball milling the BP, or just mixing the chems?

Also, are you trying to make core burners, or end burners?

 

 

I do have a few suggestions for now. Make the tube longer, 127mm to be exact. Use a larger nozzel, 5-6mm.

[Bug_X]

I have a few questions, and then I think I can help you with your problem.

 

First off, are you ball milling the BP, or just mixing the chems?

Also, are you trying to make core burners, or end burners?

 

 

I do have a few suggestions for now. Make the tube longer, 127mm to be exact. Use a larger nozzel, 5-6mm.

I don´t mill my bp.

 

I make my BP on this way, I don´t remeber the name but I think very many useing it.

 

First I take carbon and grind it in a coffygrinder, then I strain it and get a nice puder that is very fine.

 

Later i take the carbon, sulfar and dextrin in this rate 15:10:3 and mix it in a coffygrinder. The colour är now soft grey with no clods.

 

Then i dissolve the KNO3 in 0,25 L of H2O, the water is now boiling.

 

Then I mix the carbon, sulfar and dextrin in the water/KNO3.

 

When I have a solid mix I mix in about 0,5 L of C2H5OH and the KNO3 is not longer dissolve.

 

This mixer a strain (first i press out the liqiuds) out on a big plastic sheet to dry and when it is dry I rammed the rockermotor with it.

 

To one batch I use 400 g of KNO3, 75 g of carbon, 50 g of sulfar and 15 g of dextrin. (I now that I take to mutch KNO3 but some stay in the H2O.)

 

I don´t know if I try do do end or coreburner, but tonight (when I have written this) I will try some real coreburners.

 

/ Bug

[Pyrohawk]

Well for starters....don't make your BP that way! Its a lot of work and isn't very good for rockets.

 

Just powder each of the three componets seperate till they are fine powders. Then mix them togethor in a container or plastic bag and shake it up real well. Don't coffee grind them togethor, just mix them.

 

Skip all the rest of the stuff you did with the water and dextrin. Just use the mixed up powder as your BP.

 

Actually I also think you should change the dimensions a little but I would go the opposuite way that Mumbles suggests....

 

I'd try....

ID 12.5mm

Length 76mm

nozzle 3.5mm

core 10mm

[ewest]

I believe that way of making BP is called the Precipitation method. I've never read anything good about it, and why even bother when ball milling is so much easier?

 

Also the BP formula you are using of 75:15:10, KNO3:C:S will work, but for me it just sends the rockets up too fast and not quite as far as a 60:20:10 KNO3:C:S mix of BP

[Mumbles]

For end burners you want a fast fuel like 75:15:10. For core burners, you want something slower like ewest posted.

 

I don't know the proper dimensions of end burners like I do for core burners. 1/3 ID does sound reasonable because you do want more thrust.

 

Mainly I suggest figuring out if you want to make core burners or end burners. From your sizes and nozzle diameters, it sounds more like end burners. Keep the 10mm core. Start around 3mm diameter hole. If it catos, increase .5mm until it doesn't. It's a lot easier to calibrate the nozzle for a rocket, that it is to adjust the fuel for your dimensions.

 

 

 

Yes, that is what I meant.

Edited May 14, 2006 by Mumbles

[Zeppelin]

For core burners you want a fast fuel like 75:15:10. For core burners, you want something slower like ewest posted.

 

I belive you mean for end burners you want a faster fuel.

[Silverturk]

I have tried making rockets for a few weeks now. Two of probably 30 left the ground, the rest CATO:s or became a fountain.

 

I have done just like the other person who rolled his own paper tubes (I do the same), and the core and nozzle has been the same as he used. ID is 12 m''m and outside diameter is 20 m''m. Lenght is about 60 mm.

 

I've tried nozzles from 1.5 m''m to 7.5 m''m and a lot of different core lenghts, from 5 to 30 m''m. Those who left the ground had a nozzle size of about 2-2.5 m''m and a core of about 20 m''m. But that worked only once, a few attemps after that with the same nozzle and core just CATO:s. Last weekend I made an attemp with 10 rockets with different core and nozzle sizes. None of them flew! If they didn't become a fountain, they CATO:s. (I belive) this means that my paper tubes break before they can build a pressure big enough to even make the rocket leave the ground. I have rammed the nozzle with both kitty litter and plaster and a few pipeclapms around it (so the tube wont break but I can ramm it harder). But it doesent make any difference since its my tubes that is breaking.

[Bug_X]

I have been trying some coreburners and I think that works better. Some of them have lift but often catos in the air (better then cato on the ground )

 

The nozzel is now 6mm and the core is 50 mm.

 

Fist I did some static test and used the best tubes of the set and then when I tryd some rocket the tubes did´t stand it. When the new tubes has dried I will do some more tests.

 

/ Bug

[PyroJoe]

I've just been trying to dial in my 3/4" BP end burner rockets. They keep exploding on the ground! What is the general rule of thumb for nozzle length, is it 1 1/2 times the I.D. of the tube? Im using some scary fast 75:15:10 willow black powder that has been dampened and granulated without dextrin to make it even faster.

 

My nozzle diameter is 13/64" which seems pretty big, but each time the casing explodes right about the nozzle and the nozzle shoots out as well. Should I just keep making the nozzle bigger until they stop blowing up?

 

I making my nozzle lengths probably a little less than 1 1/2" times the I.D. of my tubes.

 

BTW Im using those silver spiral wound 3/4" tubes, like Kilo G sells on his site. 1/8" thick walls.

[maximusg]

PyroJoe, I think you should really try using some slower BP. If I pack my rockets with the same willow BP that I use for lift, they will cato every time. Try using some shortly milled pine BP.

[FrankRizzo]

Joe,

 

It might seem counter-intuitive, but try making your rockets without using a nozzle. A fellow named DJ experimented with nozzleless rockets and found that you could get an extremely large amount of power out of them when using hot powder. His rockets had a spindle diameter of 20% of the tube ID, and a length of 6.33 times the tube ID. You can use a long drill bit to bore 4.75" inches into the comp, using the indent created by your nozzle former as a guide.

 

Alternatively, add 20% pine charcoal to your BP to slow it down and add a nice tail.

[PyroJoe]

I think im going to try the 20% charcoal idea instead. I actually just tried a nozzless cored black powder grain and it exploded very quickly. I didn't pack the powder as hard as I could have though, and it was crumbling away quite easily. I'll just mill up some of my hardwood charcoal and mix it with my black powder, to slow it down and add a nice tail as you said Frank.

 

Thanks for the help everyone, i'll let you know how they turn out.

[gwx]

You mentioned a fast fuel 75:15:10

 

Can I use this as a propellant unmilled, end-burning without coring? Is there any chance for lift-off ?

 

Maybe someone can suggest motor diameters to me for core burning unmillied BP?

[al93535]

I use the fastest BP I can make for end burners, 75/15/10. Then I use a nozzle hole that is 1/5 the ID of the tube. I have almost no core, maybe 1 mm.

 

I suggest using 1/4 the ID for a nozzle, and using no core at all. Otherwise, if you want to use a core, use the standard 6/3/1 ratio and just screen everything together.

[psymon]

You need to use a standard nozzle diameter. Also make the nozzle a standard length with powdered cat litter.

Once you have these then try various core lengths.

My rockets have a nozzle of 5mm. I also make them with 6.5mm

Also the fuel is important, what fuel are you using? This needs to be standard all the time. If fast BP doesnt work then use a slower mix. I always use 34 carbon, 5 Sulphur, and 61 KNo3.

Now I get 100% success rate with my rockets.

[gwx]

Unmilled 75/15/10 but vigorously mixed together will still work for endburners as long as I use a small nozzle?

[Mumbles]

Gwx, are you even reading the advice people are giving? Shit, try some of their suggestions out before coming here asking us to hold your hands through your idiocy.

[gwx]

I'm so sorry

 

My main problems are that

 

I can't find the tools to do the coring

I don't have drill so drilling is not a way out

I don't believe my country sells "ball-mills" anywhere.

 

Must understand that I'm not in America so things are very very difficult for me. I'm living in a highly urbanised city so its quite hard to get the toolings.

 

Thus I wanted to try out the end-burning route which seems so much easier.

 

Just need to find a fast propellant composition and then having a standard ( but fast ) nozzle dimensions and a nominal propellant mass.

 

I'm definitely reading the advice but it just isn't really possible for me to try out cored rockets. I tried yesterday but I just can't do the core. The apparatus for making the hole only got through the 1m long tube halfway and I couldn't force more down.

 

Are you saying that I should do a core? If you want me to do a core sure I can but I guess its just gonna be hard. Just want to find an easy way out. Besides drills seem so hard and my dad does not want to take part in these nonsense.

 

I will endeavour to try as much as I can to make a core while simultaneously corresponding with friends of http://www.UKrocketry.co.uk/forum and friends of this forums so that I can successfully launch the rocket