I've made and flown several split fin rockets. All have flown straight but no whistle. I've been trying to make a rocket whistle for a while.
https://www.amazon.com/Elook-Warning-Whistles-Upgraded-Double-Sided/dp/B08B7VB3LJ/ref=sr_1_16_sspaI've made and flown several split fin rockets. All have flown straight but no whistle. I've been trying to make a rocket whistle for a while.
One way to help balance your rocket axially is to mount the batteries on the opposite side of the sled from the electronics. Mounting them all on the same side, especially in a lightweight rocket, can cause the rocket to tilt.
I've launched 4" diameter rockets that flew straight up with a 20 gram keychain camera taped to the outside of the airframe. I'm no expert but it seems a rocket would have to be really light for the course to be affected by an internal battery or a gob of epoxy. I'd fly it a couple of more times before rejecting Steve's "rockets just do some weird things" theory.Maybe the original builder put a gob of epoxy on the MM then let it dry on one side. Plausible but stupid…
Agree. It would have to be a helluva lot of epoxy to screw it up. My keychain fob is 27g and can affect the stability of a LPR. The cube SQ11 is 17g and works well. The Astrocam cam is the lightest.I've launched 4" diameter rockets that flew straight up with a 20 gram keychain camera taped to the outside of the airframe. I'm no expert but it seems a rocket would have to be really light for the course to be affected by an internal battery or a gob of epoxy. I'd fly it a couple of more times before rejecting Steve's "rockets just do some weird things" theory.
Probably overpowered until enough propellant burned off, guessing…I saw this a lot at Airfest this year. I don't think it is due to wind, but I don't know what caused it. Looking at the smoke trail left by the rocket, most maintained the same shape/angle as the smoke drifted away. If the deviation were due to wind (higher wind aloft than at the surface) the angle would increase as the upper winds carried the smoke further than at the surface.
Thingiverse. Arrow WhistleI've made and flown several split fin rockets. All have flown straight but no whistle. I've been trying to make a rocket whistle for a while.
I never use three fixed buttons on a single piece of tube. Two points define a straight line. I have used a third button on a separate section that I can rotate to align. And I really don’t like rail guides on the bottom of the rocket. I’ve seen too many twisted off while loading the rocket on the rail. Buttons are much more forgiving.
Because split fins are way cool.Why would a single stage rocket have split fins? ...
I've had it happen *several* times. I think Aerotech had a bunch of SU motors that had nozzles that burned off-center. They replaced the first pack, but the second pack had the same problem. It was obvious when you looked at the burned motor. Both launched resulted in damage to rocket.I've flown a lot of rockets over the 40+ years I've been in the hobby. This includes Estes, Centuri (that tells you how far back I go), Single use and AT RMS, and Cti motors. I've never once, not a single time, had a rocket motor fly off course due to thrust vectoring. I know it happens, have seen video of it. But it has never happened to me, which leads me to think it is a very very rare thing. When it does happen, I suspect it's due to a damaged or partially blocked (most likely by a chunk of igniter, but could be any debris from inside the motor) nozzle. I've never seen a damaged nozzle either when doing my preflight inspection or motor assembly. I HAVE had to drill out a couple nozzles that still had flash in them from casting. I'm also thinking that a damaged nozzle would adversely affect the entire flight.
On the RMS and Cti motors I've built, the nozzle fits very tight when installed properly. Of course, that means the user MUST install of the the RMS components correctly.
But again, an improperly built motor probably isn't going to burn right for the first part of the flight, have a momentary off axis thrust vector, then continue with a correct burn.
I think Steve S. had it right in his post mentioning that what happened here is the result of an over stable rocket hitting variable winds at altitude and weathercocking.
Yeah, defective nozzles, right?I've had it happen *several* times. I think Aerotech had a bunch of SU motors that had nozzles that burned off-center. They replaced the first pack, but the second pack had the same problem. It was obvious when you looked at the burned motor. Both launched resulted in damage to rocket.
Split fins, don't airfoil the edges on both sides of the gap, model gap size based on a Phoenix or Mystic Buzz, etc. AND use a high and heavy quick boost so that the rocket will coast for a while at high speed (you usually can't hear the whistle when it's drowned out by the sound of thrust).I've made and flown several split fin rockets. All have flown straight but no whistle. I've been trying to make a rocket whistle for a while.
You couldn't tell by looking at the unburned nozzle if it was good or not. When fired, it looked like someone had run a drill across the nozzle; the erosion left a groove. The rockets arced over instead of going up. This meant the delay was too long for the altitude achieved. One hit just after ejection, but before the parachute to deploy, the other damaged from the hard jerk the frame got when the parachute opened under high (downward) speed.Yeah, defective nozzles, right?
And I'm betting as long as the motor burned, the rockets were going in circles, if they didn't hit the ground first?
Right. In other words, the rocket didn't fly straight for a bit, change it's flight path, then fly straight again, true?You couldn't tell by looking at the unburned nozzle if it was good or not. When fired, it looked like someone had run a drill across the nozzle; the erosion left a groove. The rockets arced over instead of going up. This meant the delay was too long for the altitude achieved. One hit just after ejection, but before the parachute to deploy, the other damaged from the hard jerk the frame got when the parachute opened under high (downward) speed.
Correct.Right. In other words, the rocket didn't fly straight for a bit, change it's flight path, then fly straight again, true?
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