Bcorso85 Posted August 11, 2012 Share Posted August 11, 2012 Hey guys. I thought i would try something new. So I went and bought a 1# rocket tool kit from skylighter. I have tried to make 3 rockets so far. The first two just blew up. I was then using my 75 15 10 + 4.... willow b.p. So i realized where i went wrong there. I just tried my 3rd. Using a b.p. mixture of 60 30 10 4 commerical airfloat. This one, for a split second generated a wosh like it was about to take off; but then blew out the top. The clay plug and all. b.p. was roughly granulated and i pounded the propellent in smaller increments. I did give the motor a slight (!) tap because the spindle was locked on. can anyone give me a hand? Link to comment Share on other sites More sharing options...
thechewy Posted August 12, 2012 Share Posted August 12, 2012 maybe try normal bp but still in meal powder form. 75/15/10. When i try using granulated bp it almost always end up with exploding issues. I found by using meal powder,my rockets no longer explode but has very fast flights lol. The granulated black powder tends to leave tiny spaces if not packed very well becuse the flame goes thrue the spaces igniting more bp. That can cause exploding rockets unless maybe the issue is the tubes not strong enough for the pressure. Whats your engine sizes? Lenght,diameter,many things could be the issue. Also the more expirienced rocketry pople here may have better info on this..just give it time fo replies and i hope things work out for you maybe try normal bp but still in meal powder form. 75/15/10. When i try using granulated bp it almost always end up with exploding issues. I found by using meal powder,my rockets no longer explode but has very fast flights lol. The granulated black powder tends to leave tiny spaces if not packed very well becuse the flame goes thrue the spaces igniting more bp. That can cause exploding rockets unless maybe the issue is the tubes not strong enough for the pressure. Whats your engine sizes? Lenght,diameter,many things could be the issue. Also the more expirienced rocketry pople here may have better info on this..just give it time fo replies and i hope things work out for you maybe try normal bp but still in meal powder form. 75/15/10. When i try using granulated bp it almost always end up with exploding issues. I found by using meal powder,my rockets no longer explode but has very fast flights lol. The granulated black powder tends to leave tiny spaces if not packed very well becuse the flame goes thrue the spaces igniting more bp. That can cause exploding rockets unless maybe the issue is the tubes not strong enough for the pressure. Whats your engine sizes? Lenght,diameter,many things could be the issue. Also the more expirienced rocketry pople here may have better info on this..just give it time fo replies and i hope things work out for you Link to comment Share on other sites More sharing options...
The504 Posted August 12, 2012 Share Posted August 12, 2012 (edited) I used 75/15/10 meal on my Nozzled 4oz rocket yesterday and it blew up. Too Hot. Edited August 12, 2012 by The504 Link to comment Share on other sites More sharing options...
californiapyro Posted August 12, 2012 Share Posted August 12, 2012 guys, you can't use 75/15/10 in a cored nozzled rocket, regardless of milling. 60/30/10 is much better, and try wetting and screening the mixture, then letting it dry before ramming it. This helps the powder stay compact as a fuel grain. Increments no larger than 1 ID, and a nozzle at least 1 ID tall Link to comment Share on other sites More sharing options...
mabuse00 Posted August 12, 2012 Share Posted August 12, 2012 (edited) Hi, Using a b.p. mixture of 60 30 10 4 commercial airfloatWhat's the 4 standing for? I hope You did not use any dextrine in there?Because in this case what the chewy wrote might apply here, you cannot compact it very well. I've got a 1lb tooling too, and I found it very hard to get consistent results with ramming, as opposed to smaller rockets. Lot's of explosions. I think this size is already too big to work without a press. You simply don't get enough density. If you cannot get it working, maybe nozzleless is an option for you. For 1lb rockets I only use the nozzleless configuration, it's much more reliable, especially when you don't have a press.I got about the same usable payload capacity with nozzleless compared to nozzled, even with simple screened together and wet granulated 75-15-10 green mix, no oil. Another method I'm going to try next is to use 75-15-10 green mix in a nozzled rocket and add oil to it, this will slow it down and create a denser fuel mass, making the whole thing much less critical and more independent from moisture exposure. I had great succes with this method on smaller calibres. Edited August 12, 2012 by mabuse00 Link to comment Share on other sites More sharing options...
dagabu Posted August 12, 2012 Share Posted August 12, 2012 Oil will defenately slow the burn but be careful to only use a little, it will slow the fuel WAY down real fast. -dag Link to comment Share on other sites More sharing options...
californiapyro Posted August 12, 2012 Share Posted August 12, 2012 I will vouch for that. I have used 75/15/10 with 5% oil, and it barely got off the pad with no header. Same BP, 1% oil gave me a bullet-like flight. Link to comment Share on other sites More sharing options...
mabuse00 Posted August 12, 2012 Share Posted August 12, 2012 I use paraffin oil, sold as lamp fuel, and use 2%. I would estimate my standard 75-15-10 oilfuel to be about as fast as 68-22-10 fuel without oil.Or maybe a little slower but not much. And it's very nice to work with this stuff. The motor comes of the spindle with ease - one of my biggest problems when I started. And there is no dust Link to comment Share on other sites More sharing options...
thechewy Posted August 12, 2012 Share Posted August 12, 2012 i just make my bp for lift powder/rockets/fuses all with the 75/15/10.just add 10%dextrin for my fuses,it mkes them pretty stiff and sharp bends dont seem to affect them at all. My rockets are cored mostly now that i started using plain meal powder in them. If grained bp is used i tend to make end burners. Butt my cored meal powder rockets fly so fast that i cant keep track unless i follow the smoke trail lol. They are extremely fast and the fastest i ever made or seen." i've bought countless numbers of rockets in my lifetime" but the ones i make exceeds my expectations alot! I rarely make a header for them being i just like to see how high and fast i can make them go:) btw my first rockets used Rcandy with iron oxide,just always had problems gettng them out of their casings Link to comment Share on other sites More sharing options...
Juiceh Posted August 14, 2012 Share Posted August 14, 2012 What kind of tubes are you using? Are you using a tube support? Link to comment Share on other sites More sharing options...
Bcorso85 Posted August 19, 2012 Author Share Posted August 19, 2012 Thanks guys. There is ALOT of information here. Should I not mill my B.P.? Just granulate some scratch mix? I'm using 7.5 inch motors, 1 inch o.d. 3/4 i.d. If i make a granulated scratch mix should i omit the dextrin? May I use my willow for alittle extra kick in a weak powder? Another option ( Im just clarifying here) is to ball mill a hot b.p., but not granulate it and just ram the meal dust fresh out of mill? Maybe a weak milled powder 60 30 10 (no dextrin and commercial airfloat?) Thanks guys im just alittle overwhelmed with the variables and options for differnt performances. Link to comment Share on other sites More sharing options...
dagabu Posted August 20, 2012 Share Posted August 20, 2012 Thanks guys. There is ALOT of information here. Should I not mill my B.P.? Just granulate some scratch mix? I'm using 7.5 inch motors, 1 inch o.d. 3/4 i.d. If i make a granulated scratch mix should i omit the dextrin? May I use my willow for alittle extra kick in a weak powder? Another option ( Im just clarifying here) is to ball mill a hot b.p., but not granulate it and just ram the meal dust fresh out of mill? Maybe a weak milled powder 60 30 10 (no dextrin and commercial airfloat?) Thanks guys im just alittle overwhelmed with the variables and options for differnt performances. I suggest that you do ballmill your BP then whet it and rice it without any dextrin. If you blow up rockets, add 5% more charcoal (nicer tails) before ricing the BP but dont ballmill it in the mix. If you just make 75:15:10 BP and ballmill it, you can use it for coating rice hulls, star comps, lift, break etc... -dag Link to comment Share on other sites More sharing options...
Bcorso85 Posted September 16, 2012 Author Share Posted September 16, 2012 Its been a while since i posted so I thought I'd update you guys. My b.p. rockets are still blowing up. My last try was 60-25-15-5 green mix that i riced. And this time I used commercial air float charcoal. Some thing I thought would slow the fuel down. After all that hammering i was certain I compressed the grain well enough. But i guess not. To slow the fuel down is mineral oil ok? Link to comment Share on other sites More sharing options...
dan999ification Posted September 16, 2012 Share Posted September 16, 2012 (edited) i wouldnt put oil in 60/30/15 it will probably be useless, you say the tubes are 3/4 inch id 1inch od, thats a thin wall for this size, my 1 pound tubes are at least double 4.75 iirc im suprised you can ram in a thin tube and get the density you would need without breaking the tube and blowing the motor, loose fuel makes more pressure as more is consumed, thin tubes unless you got nept or very good homemade cant take the pressure. Dan. Edited September 16, 2012 by dan999ification 1 Link to comment Share on other sites More sharing options...
mikeee Posted September 16, 2012 Share Posted September 16, 2012 Use a tube support sleeve and press the fuel with a hydraulic press.This would solve most of the problems. (solid fuel) Link to comment Share on other sites More sharing options...
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