8 replies to this topic

[pritch]

Hello. I've had an interest in anything pyro for allot of years,(19 now) I've just ordered 500 grams of kno3 and 100 grams of suphur which cost me around 13 quid including delivery. Unfortunatly I can't find garden direct anywhere.

So basically I want to make some rocket motors and would like advice on safety issues and performance. The ingredients I have are: kno3, sugar, sulphur and a bag of barbecue charcoal. My main safety concern is the melting process if I want to make solid propellant. All I have is my cooker. Also how well could you expect a nicely ground but dry mix of kno3 and sugar or possibly other ingredients to perform?

I can't find any sites that have data on just the basic kno3 rockets, in small sizes anyhow. What sort of class would you put your dry mix end burning motor into?

I will probally think of more questions.

Thanks and nice to meet you people!

[Yugen-biki]

Hello!

A rule of thumb is "the larger the engine gets the less kno3 the mixture should contain". I?m using 68:23:9 (kno3:C:S) for my (ID 13mm) rockets. I?m using a rocket tool like the ones found on skylighter and firefox etc. But mine is home made. A tool of some kind is a muts. I use 80% kno3 and 20% sugar as a delay on top of my rockets, and to ensure that the fuel stays solid. I mill both the "BP" and sugar delay until a very fine powder. This is very important or else the "BP" fuel doesn?t stay solid.

http://www.wfvisser....t_tools_EN.html

This site is were I first got inspiration some years ago (The E6 engine).

A lot of info can be found in this forum.

[Phoenix]

I think the first fireworks I ever made were "5 cent sugar rockets." They used the following formula (which is all over the Internet, so you've probably seen it before)

Potassium nitrate...63
Sucrose..................27
Sulfur.....................10

The ingredients were just ground in a pestle and mortar and mixed by hand, then rammed into the case. They worked great! However, now I only ever really use BP type rocket propellants, since the sugar based ones don't have much in the way of a tail, and are a little hygroscopic. There are several suggestions for BP propellants in this topic.

Wouter includes a sleeve in his set of tooling. This isn't always necessary - I've never used one.

Garden Direct's site isn't really there yet, but the beginnings of it are at www.gardendirect.co.uk. The email address there doesn't work, but you can phone them and ask for a catalogue.

[maxman]

I've used the sugar propelant as shown by Phoenix, apart from the hydroscopic nature and the lack of tail I found that to get them to work good they had to be primed by pouring fine bp up the long core so that the length of the core ignites at once!

It didnt take me long to realise that if I had to make BP to do this then I may as well make the whole rocket out BP and do away with the priming.

You cant beat BP for your rockets.

Has anyone got skylighters or any other tooling dimensions for a 1lb rocket?
how long for the spindle etc? I seem to be ok now with my 12mm id x 80mm rockets but want to make a decent 19mm id now. I tried on last night that was 19mm id x 80mm using a basic 1 lb stinger spindle but with no side vent. It left the launch tube so faaaaassst that it had no visual efect at all!

I used meal &10%C I guess I would need a longer core and slower BP.

Anyone had sucess with one that they would like to share??

Thanks.

[Rhodri]

Hi Maxman

I've used 'straight' 75:15:10 BP in some 10mm id rockets. However, since I've now just about perfected my BP, using this newer BP alone is simply too 'hot' for rockets - even with the addition of 10% C - it's just too 'quick'!

So.....this is what I'm currently using for my 20mm rockets:

Based on a Lancaster mix - 61:34:5 I've developed the following:

61:34:8 - Slightly more S and the 34 is C made up as follows 20:Willow 14:Lumpwood.

The 14 lumpwood gives REALLY good sparks to the tail.

We're not quite done yet though!

I make up 100g's of the above 61:34:8 then add 20% of fast 75:15:10 BP.

Mix but don't mill and you're done.

Use this for the larger rockets - I think you'll be impressed at the power of the lift and elegance of the tail.

[maxman]

I guess it all depends on the length of the core though as well.
I'm looking really to make something 19mm x 130mm or so using a 6mm dia spindle. So I really wanted a longish core for lifting a decent payload.

[chim-chim]

Pritch,
First let me say, if you're going to use KNO3/Sugar rockets, I'd expect nearly all members of this forum would yield to the experience of Richard Nakka. A web search will find him easily, and I would highly recommend doing so.

Onwards-
I'm afraid you won't find a bunch of info on end-burning rockets. Core burning is considerably more common. Conventional wisdom has it that KNO3/sugar doesn't have the power, and anyone making their own BP is likely into pyrotechnics and will shortly graduate to the increased lifting power of core burning.

That said,
I've been working with a mix of 65:34:1 KNO3:Sugar:Fe2O3. The Sugar is normal confectioners, the Fe2O3 (iron oxide, red- available nearly pure as concrete colorant) is a catalyst, increasing burn rate 1.6-1.8 times, making an end burner feasible.
I use this mix w/o melting, in tubes w/ an inner diameter ranging from 1/4" - 3/4", with a nozzle roughly 1/4 the I.D. of the tube. My largest isn't big, 3/4" I.D. a little over 3 inches long, contain up to 20g of fuel or so, case, nozzle and stick another 12g or so. For the nozzle, I use tooling and clay now,
http://deskmedia.com...tbn/HAROLD1.htm
but got good performance from both Durham's Rock Hard Water Putty and Epoxy. I poured them into tubes standing upright on a coffee can lid. Whereas neither will stick to lid very well, they snap off easily leaving a very smooth end when set. Ram the powder with a non-sparking dowel, pick the right stick and you're flying. These aren't going to lift shells too well, but put their own weight few hundred feet and can carry a few small stars, bits of flying fish, etc.

My BP and core-burner rocket knowledge is academic only, so I'll give the podium back to someone with practice.

Did I mention gloves, goggles, long sleeve cotton clothes, extinguisher nearby, no smoking, the kitchen is for food.

Stay Safe, I'd hate for someone to blow themselves up listening to me,
I might be wrong, and so might anyone else, always get as much info as you can and double check everything.


chim

[pritch]

Thanks very much for the advice guys, I will be taking all of it into account. I've decided to start off with making meal and possibly pulverone for my first attempts because it looks allot safer and easier. So I will be making fireworks more than rockets really. If I am going to make bp or solid sugar kno3 motors I think I better wait till I have a blast screen and possibly some way of monitoring melting temperature.
It may come this morning as well. I can't wait!

[BigG]

I tried on last night that was 19mm id x 80mm using a basic 1 lb stinger spindle but with no side vent. It left the launch tube so faaaaassst that it had no visual efect at all!

I?ll consider that a good thing! Rockets are not really impressive on the way up. If your rocket is so powerful then it can probably carry a good payload. Good payload means great finish!

If you want a good tail you can try adding 3%-6% of Coarse Ti or Fe-Ti, but don?t expect anything too spectacular from rockets with a motor of 1 inch and below.