| MadSci Network: Engineering |
Dear User, In order to stablize rockets, the fins have to be a) very straight and b) broad enough to provide balancing forces at the speeds which your rocket is moving. By the sound of it, your fins are *not* very straight - and when you launch your rocket it does not have enough time to gather sufficient speed. If your speed is too low, small fins would not provide adequate stabilization. And of course, even at high speeds if your fins are not straight or not aligned, your rocket would be unpredictable. Another factor involved is the centering of the nozzle. If the nozzle is not well centered, your reaction force vector will not be aligned with the directional vector of the rocket, resulting in gyrations and finally 'bouncing along the ground;. You should also pay attention to the centre of gravity of the rocket - depending on the application it usually should be towards the back of the rocket, close to the point where the reaction force is generated. All in all, the smaller is the rocket, the harder it is to stabilize it because of the increasing effects of small errors in manufacture. That is why pyrotechnic rockets mostly use two simple and proven methods - the stick and the 'twist' nozzle instead of fins. All the above brings us to the sad point - you should NOT be taking apart Estes rockets and stuffing the 'gunpowder' into makeshift constructions, *especially* if you lack the knowledge of how to construct reliable engines. Since your rockets are (hopefully) small, the danger is not too great, however, even a small rocket can easily destroy an eye, or set your hair/clothes on fire. While decorative scarring is the going rage in beauty world, I suspect that hideous charred scars and missing eyes/fingers are not going to make you very attractive to the majority of the population. Moral - play safe, and always wear safety goggles. Cheers, A.G.E.
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