Cone Shaped Rockets

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Okay, F-14 rocket is pretty much finished.

Final Stats:
Height: 34 Inches
Bottom Diameter: 12 inches
Weight (with E-9 engine and parachute): 14.5 oz
CG (when loaded): 23.25 inches from tip
The fins protrude another 3.5 inches out and down an extra 3 inches.

**How much nose weight, if any, do all of you think would be appropriate?

DSC03002.jpg
 
The max recommended lift off weight for the wussy E9 4 motor is 15 oz. With the drag of the cone it is even worse. Get a more powerful motor and weight it up to get the cg above the CP to your taste. If the motor can handle that weight you are OK with a long rod on a calm day. A semi wussy E 12 4 is 17 oz. A real man 24 mm composite will do the trick. Power, nose weight and base drag are three of the four friends any oddroc flyer can ever hope to have. Use them. love them.
 
Hmmm... Well I'm thinking, like you said, it might be okay to launch off long rod on calm day. It weighs considerably less than my RC Glider that launches on an E9 after all (though that one is obviously underpowered). I think it will do for my first scratch-build cone attempt, just have to bee careful.

I'm already thinking of plans for the F-16, a conical rocket with multiple stages (up to 3). I think I'll give it a considerably narrower profile making it easier to balance. It would start with a much smaller cone that runs off of an 18mm on top, then a stage that just continues the cone shape running on a 24mm (decent by 9-12in parachute, and if that works well a bottom stage running on a composite F or G. Over all it would probably be similar in bottom diameter but perhaps a foot or more longer. Possibly a scale model of the Space Probe Rocket as seen in Disney's "Man in Space" (1955), I'm already working on another RC rocket glider from the same show after all.
 
Alright! Had 5 flights on the F-14 last Saturday, just put the first one on Youtube:
[video=youtube;9N5EvVX_eAo]https://www.youtube.com/watch?v=9N5EvVX_eAo"]https://www.youtube.com/watch?v=9N5EvVX_eAo[/video]
All 5 flights ended in various crashes, the rocket is light but the very high drag gives it a low speed off the wire causing it to go badly. Even a borrowed composite E did not do it. As it turns out, the construction I used gave it an incredibly strong nose, alas the nose was finally destroyed on the 5th flight.

I have already almost finished repairs, it will have a much different nose, can be launched from a much larger (and longer) rod, and I plan to get some F motors in 24mm to launch it on, should work a lot better with those.

Also flew a scratch built scale Mercury-Redstone and Gemini (one of the clear fins broke tho, not sure how I'm gonna fix it.

F-14 Maiden Launch.jpgF-14 Lawn Dart 3.jpgF-14 Lawn Dart 2.jpgF-14 5th crash.jpg
 

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I must say, that actually looks cool with the fins, maybe even better than a pure cone could. But this thing's draggier than a M powered level 3 rocket. Even with the most powerful 24 mm motor available, I doubt the burnout to apogee time is more than 1 second.
 
Yeah all these flights were done on various Es, I was thinking maybe a 24mm F or even a G if it can be got that has a delay of no more than 3 seconds. Wont go high but should have enough to fly straight and deploy before ground.
 
Yeah all these flights were done on various Es, I was thinking maybe a 24mm F or even a G if it can be got that has a delay of no more than 3 seconds. Wont go high but should have enough to fly straight and deploy before ground.
Both Estes and AeroTech have E-30s. These would give you ~1.3 seconds of good thrust so less time to arc and go into the nearest wood :)
 
Dave,

Thanks for the information! This reminds me of my WVB Shuttle. It crashed on a D12-4, which was way too under-powered. It had an arcing flight similar to your F-14, but not as high. I am in the process of re-building. I was thinking that a composite E-motor would be sufficient, but now your experience has got me wondering. Please keep us posted on what you find out. I agree that your F-14 looks similar to the Walt Disney/Wernher von Braun (Man In Space) Space Ferry/Cargo Rocket.
 
I think the T tail offset drag is the least of your worries, the cones will be base draggy and won't have a lot of speed, meaning the offset drag won't be as big of an issue.

Frank
 
4th launch was on an E24, not noticeably different.

I've been looking at this F44:
https://www.csrocketry.com/store/f44-4w-2-pack.html

It is still 24mm and will fit in the mount. Still has a 4 second delay though.

An F 44 4 would be great. Depending on your mount you can also look at Cessaroni up to the 6 grain. There are other ways but they can lead to the dark side. I always use the old Patton saying "when you stick your hand into the pile of goo that used to be your best rocket, you will know what to do." Just like the movie you will hear trumpets on the horizon in the cold dry air of the desert morning. Just a little more blood and guts needed on that oddroc.
 
Yeah all these flights were done on various Es, I was thinking maybe a 24mm F or even a G if it can be got that has a delay of no more than 3 seconds. Wont go high but should have enough to fly straight and deploy before ground.

Normally drag favors a long burn but it's heavy enough to prefer the higher thrusts when limited to 24 mm.

I ran a quick and dirty sim and the terminal velocity is about 45 MPH. A robust recovery system should be able to handle that even way late. However the rocket I made with 2 seconds burnout to apogee kept spearing the parachute so I had to go to streamer for simplicity. Rear ejection would avoid that problem. Other than that, it should be able to eject before hitting the ground if it goes straight enough. I came up with 200' on E9 (theoretical), 323' on F24, 656' on G65; 29 mm would be able to do 359' on F15s and 800' on the 3-grain G33.

View attachment TRF-cone12inch0.ork
 
Dave,

Thanks for the information! This reminds me of my WVB Shuttle. It crashed on a D12-4, which was way too under-powered. It had an arcing flight similar to your F-14, but not as high. I am in the process of re-building. I was thinking that a composite E-motor would be sufficient, but now your experience has got me wondering. Please keep us posted on what you find out. I agree that your F-14 looks similar to the Walt Disney/Wernher von Braun (Man In Space) Space Ferry/Cargo Rocket.

Yeah, I have now posted videos of all 5 flights on my Youtube: https://www.youtube.com/user/evildave42a/videos. The 4th one "F-14 Lawn Dart" was on an E24. You will notice virtually no difference in performance from the E9. This rocket is just too draggy for it to make a difference. I looked up the thread on your WVB, at that size and weight I would definitely go with an F, these cone shapes are really draggy. Also if it's not too hard I recommend redoing the launch lugs to accommodate a 1/4 inch rod, you saw how mine turned over due to low launch speed before straightening out once it had accelerated (not the first time I've had this problem), the 1/4 inch rods can be much longer and keep it a bit more stable at launch, I'm doing it to the F-14. Beautiful rocket, hope it was not damaged too badly.
BTW: If an F proves to be too much you can always put an adapter for an E in it.

Well after the refurbished F-14 proves itself I will be moving on to either a scale Man In Space rocket like Aerostadt's, or a 2-3 stage cone rocket (where the cone is continued throughout the stages), either one is going to be built with the Estes black powder F15 in mind, that might change though.
 
By the way Aerostadt, this reminds me of my other project, I've been building my second radio controlled rocket glider the F-15 Thunderwing Mk.II. It is modeled after the same WVB Shuttle/Man In Space space-plane as the one on your rocket. It will have a 62 inch wingspan and is designed to be launched at about 40 degrees up on a G80. Don't think it will go real high but it will look great. I would have concentrated on it more but I realized that even after finishing it I will have to make a new launch easel that is much stronger with longer rails to keep it more stable on lift off.

I have been considering a much lighter RC glider for a D12, but after seeing your rocket I start to wonder again if I can make one small enough to fit on a cone booster running on a G. Perhaps have the glider air-launch off the booster on a C5 or something if I can make it small enough.

Anyway you can find the build log and some pics for the F-15 here: https://www.rcgroups.com/forums/showthread.php?t=2376537
 
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