Mister Rogers
Active Member
- Joined
- Oct 24, 2004
- Messages
- 43
- Reaction score
- 0
Can anyone help me with interpreting the results of swing tests on scratchbuilt rockets? As a youngster, I always had trouble with this, and as a BAR, I am still having trouble with this. Oddly enough, even when the results of my swing tests tell me the rocket is horrible, I use my intuitive common sense regarding length, fin area, weight, motor size, etc., when I am designing them so I say "what the heck, I think it will fly okay despite the swing test" and it fly it anyway. They have always flown well and I have never had one become unstable.
What I do for the swing test is to prep the rocket just as if I am going to launch it with the engine (minus igniter) and wadding and chute. I then find the exact balance point (cg) and tie my string on with a slipknot and tape it in place. Then I go outside and swing my heart out. Sometimes it fly backwards, straight as an arrow, sometimes not. I would only worry if it "wobbled" in the swing test. I just tested one yesterday of my own design, sort of like a sidewinder missile but with a long ogive nose. It flew perfectly straight up and down, or vertical to the ground, just like it was sitting on a lauch pad, and perpendicular to the direction of "flight". It is a longish rocket, but with those huge fins I could't imagine it being unstable. I tried putting progressively more noseweight into it with same results. I've got almost as much noseweight as rocket! And it still sits straight up and down in the swing test, and I am swinging this thing as fast as I can. please help me....
What I do for the swing test is to prep the rocket just as if I am going to launch it with the engine (minus igniter) and wadding and chute. I then find the exact balance point (cg) and tie my string on with a slipknot and tape it in place. Then I go outside and swing my heart out. Sometimes it fly backwards, straight as an arrow, sometimes not. I would only worry if it "wobbled" in the swing test. I just tested one yesterday of my own design, sort of like a sidewinder missile but with a long ogive nose. It flew perfectly straight up and down, or vertical to the ground, just like it was sitting on a lauch pad, and perpendicular to the direction of "flight". It is a longish rocket, but with those huge fins I could't imagine it being unstable. I tried putting progressively more noseweight into it with same results. I've got almost as much noseweight as rocket! And it still sits straight up and down in the swing test, and I am swinging this thing as fast as I can. please help me....