17 replies to this topic

[Matt]

I have a question for all of you rocket boys out there. What is the most effective propellant for a rocket with a 23mm ID. Length I can adjust easily. I know that for my little rockets BP would be the most effective. I use BP in my 15mm engines and "teleflite propellant" in my 23mm engines. They work well but I was curious what would be the most suitable propellant for that size rocket. Candy propellant? BP? or some other magical mix :duh: Just bare in mind I dont have AP or any of those amazing oxidisers. I dont really care for tails or anything, this is purely for my mode; rockets (never buy them, making them is much more fun and challenging) Cheers.

-Matt

[bernie]

Can't imagine why a bp propellant could not be used. The shorter spindle length will require a stronger (milled) comp. Not sure if this is what your after Matt. Let's sort it out.

[Matt]

Im not even that sure what im after, i was mainly just trying to start a convo I personally believe that BP is the "ultimate" fuel. It can be very strong, it looks beutiful in flight and relatively simple to make. The only set-back for me is that I dont really enjoy making batches of BP. I can whip up a 100g batch of teleflight in 5 minutes no problem. BP on the other had takes me a bit longer, I have to grind up the charcoal and..... well thats the only bit I dont enjoy. I havnt got my mill up and running yet, I made my mill jar over the weekend. I have yet to get a motor and the drive-wheelie thingies. After I get my mill up and running making bp rockets this size wont be a problem at all ( I consider 23mm to be a large rocket, I dunno about the rest of you ) I also use these rockets to take up my 2 inch canister shells. Oh yea and Bernie, It turns out I had taken a photo of the shell in my avatar when it was spiked, I'll put it up on my site shortly.

-Matt

[bernie]

I have always been under the impression that Richard H was a rocket guy. Maybe he can shed some light on the subject for you.

[Richard H]

For pyrotechnics, black powder is your best fuel. Composite fuels using ammonium perchlorate are much more powerful, but hard to make.

I would have throught blackpowder would be a better fuel than sugar based propellants really, although sugar based propellants are used because they can be easily cast into tubes.

[bernie]

There you have it.

Though the charcoal aspect is a little messy at this point for you Matt, when all is said and done an established method goes a long way. There is nothing that says you cannot experiment but you will have to base it all on something and a lot of time will be spent getting it to your liking. Keep very careful, detailed notes.

[chrissw]

Hello,

What is "teleflite propellant"?

I cannot find any reference to it anywhere on the net.

Regards,

Chris.S.

[Richard H]

http://www.google.co...eleflite rocket

Ever heard of google?

[chrissw]

Well I'll be blowed, I usually use the virgin search engine then "jeeves" and neither of them brought up anything at all!

Many Thanks.

[Stuart]

Jeaves is something that I cant say becuase I wouod be bannd from the forum but lets just say it is anything but good. Virgin search will be crap because it is an own brand search engine. Use Google and then Altavista if Google doesnt bring anything up.

[chrissw]

Cheers!

[OxCid]

if you really get desparate use www.metacrawler.com it takes a while to do the search but u nearly always get something.

[Robbie414]

For pure rocket applications use sugar/oxidiser see http://www.nakka-rocketry.net/

Bernie - Sugar = Candy :-)

Easy to cast, potentially more useful and easier to 'tweek'. 70/30 doesn't get much easier Just remember when you are casting that there should be no flames used as a heat source. A great way of doing it is with and old deep fat fryer used as an oil bath, stable heat source and should not reach temperatures that will ignite the comp. I agree with you on the black powder 'making' option, its fun at first but a ball ache after a while.

Why not make yourself a reuseble engine? with replacable Potassium Nitrate/Sucrose grains. MMMMM the smell...its all about the smell...:-0

I made some epoxy grains at Uni, they are really really easy to cast (no heat). You need to make a 'real' motor out of preferably a stainless steel, to which you can add various sensors for use in testing (not compulsory) and a nice titanium nozzle (scrounged some scrap from a foundry). We are talking about 1000PSI here so its sure is an adrenaline rush when you fire one!

Have fun and let us know how you get on..

Rob

[Matt]

Those epoxy grains sound very interesting, Ive been reading richard nakka's write up on them for the past ten minutes. I really would like to give that one a shot. The "candy propellant" never turned me on to be honest, kindof a bad first impression ruined it, I just couldnt get it to lift my little rockets (I never cooked it so you cant really expect it to work) and so i moved on to other propellants. I dont really feel too comfortable with the cooking either, gives me the heebie jeebies I'll make a note in my handy dandy note book of pyro goodies to try out the epoxy grains. I cant really launch any rockets that large around here, dense residentual area. So i'll try it out when i get to my mates house with a nice big property, I think ive dribbled enough crap for one day. Adios

-Matt

[leniol]

That epoxy proplellant is a nightmare. Very difficult to put into tubes & ignite. I have to admit that the KNO3 wasn't very finely ground though...