propeller recovery??

[techrat]

Ok, I'm thinking about a rocket with three ducted fans attached. The ducted fans act as the fins on the way up, and the props inside the ducted fans provide some type of autorotation/helicopter recovery on the way down. No motors, just air drag on the props causing them to spin to ease the rocket back to the ground. Or would that resistance create too much drag on the way up? just throwing out an idea here, one that's probably been discussed before and I just haven't checked the archives because I'm stupid. ;-)

 

[lakeroadster]

Ok, I'm thinking about a rocket with three ducted fans attached. The ducted fans act as the fins on the way up, and the props inside the ducted fans provide some type of autorotation/helicopter recovery on the way down. No motors, just air drag on the props causing them to spin to ease the rocket back to the ground. Or would that resistance create too much drag on the way up? just throwing out an idea here, one that's probably been discussed before and I just haven't checked the archives because I'm stupid. ;-)

It would be a challenge to make the fans big enough to work to slow down the rocket's decent, yet light and aero enough to not hinder the rockets ability to reach a respectable apogee.

But it would make for a neat looking rocket.

Maybe instead of propeller style fan blades, use flat panels that are open during flight, but then close at apogee. Kind of like blinds on a window.

 

[KenECoyote]

Maybe instead of propeller style fan blades, use flat panels that are open during flight, but then close at apogee. Kind of like blinds on a window.

That's an idea I have for a future saucer build.

 

[KenECoyote]

Yup, along Lakeroadster's lines, generally for rockets you want less drag going up and more coming down (saucers are a kind of exception in some cases where drag is the same both ways).

So if you really do want a propeller design rocket (excluding copter styles), I think it would be better for the props to be mounted in the rear and spinning the way up (providing a bit of rear drag for stability) and then locked on the way down to slow the descent.

Now build one!

 

[Zeus-cat]

I also think the propellers would have to be fairly large in relation to the rocket to provide sufficient drag on the way down to be useful. The Estes Skywinder is somewhat similar to what you are thinking of. It is a heavy rocket for a B6-2 or a C6-3 and the rotors deploy at motor ejection so fairly reduced drag on the way up.

 

[Steve Shannon]

Anything that results in a safe terminal velocity during descent will greatly reduce the terminal velocity on ascent unless stowed until needed.

 

[lakeroadster]

Anything that results in a safe terminal velocity during descent will greatly reduce the terminal velocity on ascent unless stowed until needed.

Let's not stifle creativity. Ideas such as the closing shutter door concept discussed in the 2nd and 3rd post visually would look the same on ascent / decent but would produce a drastic increase in drag on descent.

 

[Steve Shannon]

Let's not stifle creativity. Ideas such as the closing shutter door concept discussed in the 2nd and 3rd post visually would look the same on ascent / decent but would produce a drastic increase in drag on descent.

I can see where you might think my post would discourage creativity, but it was more intended to emphasize the need for some change in configuration. Your post in #2 is a good example of what I meant by stowing. I like Ken E Coyote’s post #4 also.

 

[icyclops]

Air baffles?

 

[icyclops]

That's an idea I have for a future saucer build.

Called air baffles ….for slowing down a rocket…some military armament uses such a technique….but again, the fins would either need to open up and the blinds big enough to catch enough air to produce a lot of drag….think the fins if not moved to horizontal position at apogee would have to be big big….good luck!

 

[techrat]

Ok, totally new idea but related to this idea: Long body tube with two or three prop blades hinged at the nosecone so they are parallel with the body of the rocket at launch. At the ejection charge, instead of popping off the nosecone, a piston pushes against the hinges, pushing the prop blades to 90 degrees versus the body tube, and then drag does the rest, and the body of the rocket simply spins downward for recovery. I'll upload some napkin drawings when I get a chance.

 

[kalsow]

Ok, totally new idea but related to this idea: Long body tube with two or three prop blades hinged at the nosecone so they are parallel with the body of the rocket at launch. At the ejection charge, instead of popping off the nosecone, a piston pushes against the hinges, pushing the prop blades to 90 degrees versus the body tube, and then drag does the rest, and the body of the rocket simply spins downward for recovery. I'll upload some napkin drawings when I get a chance.

Like one of these??

https://www.apogeerockets.com/Rocket-Kits/Skill-Level-4-Model-Rocket-Kits/Gyro-Chaserhttps://www.apogeerockets.com/Rocket-Kits/Skill-Level-4-Model-Rocket-Kits/Heli-Roc

 

[techrat]

Like one of these??

https://www.apogeerockets.com/Rocket-Kits/Skill-Level-4-Model-Rocket-Kits/Gyro-Chaserhttps://www.apogeerockets.com/Rocket-Kits/Skill-Level-4-Model-Rocket-Kits/Heli-Roc

Nevermind.... Clearly, my idea has been done before. By everyone. I'm trying to avoid parachutes and streamers and I'm looking for a recovery option that doesn't involve stuffing something inside the body tube... Particularly something that has a tendency to melt. And is it just me or are chute lines a PITA? Heck, I'll settle for a gas cartridge of helium that inflates a balloon at apogee.

 

[Woody's Workshop]

I like the Heli-Roc. Would be a cool and challenging scratch build!

 

[lakeroadster]

Ok, totally new idea but related to this idea: Long body tube with two or three prop blades hinged at the nosecone so they are parallel with the body of the rocket at launch. At the ejection charge, instead of popping off the nosecone, a piston pushes against the hinges, pushing the prop blades to 90 degrees versus the body tube, and then drag does the rest, and the body of the rocket simply spins downward for recovery. I'll upload some napkin drawings when I get a chance.

@BABAR has done this and made it "look" easy. Don't give up on the air baffles. Three large ring fins, with baffles that snap shut at apogee....

 

[BABAR]

Ok, totally new idea but related to this idea: Long body tube with two or three prop blades hinged at the nosecone so they are parallel with the body of the rocket at launch. At the ejection charge, instead of popping off the nosecone, a piston pushes against the hinges, pushing the prop blades to 90 degrees versus the body tube, and then drag does the rest, and the body of the rocket simply spins downward for recovery. I'll upload some napkin drawings when I get a chance.

I have several heli and air brake rockets, which use rubber bands for deployment and separate ones for motor and and retention.

However, I am working on something very much like your idea at present. You don't need pistons, you can put vents under the forward or mid portions of the blades, put some foil on the blades where the vents are, and the ejection charge will "blow" the blades away from the body. My design is set so that the nose cone holds the blades in place on boost, when the nose done blows off, the blades are released (hinges are in back), at this point the blades are minimally deployed, the rocket should fall nose first (my current version failed here because nose wasn't heavy enough and it fell TAIL first), and drag should open blades. The blade stops are strings or ribbons attached to the outside of the body tube, inside of the blades, that stop the hinges at just past 90 degrees. You CAN incorporate the fins into the blades.

Great minds think alike! I look forward to your drawings.

 

[Stefan2k4]

If you're going to use ducted fans as a recovery deivce, what about the idea of using them as reverse thrusters? There used to be a kit from heavenly hobbies that used an engine mounted in the nose as a "retro rocket". I would think that ducted fans would be an even more effective and controlled method of doing something like this as you could have a small flight computer that could control the fans and ensure more reliable operation. Of course this wouldn't be easy, as the motors, batteries, and flight computer would all add wieght. Also youd probably have to develop your own software to run it all. Perhaps super capacitors could be used instead of batteries to reduce weight as the motors would likely have a short run time. Anyway, it would be a bit of a challenge, but would make for a pretty cool flight.

https://www.rocketreviews.com/heavenly-hobbies-backdraft--by-dick-stafford.html

 

[icyclops]

Ok, totally new idea but related to this idea: Long body tube with two or three prop blades hinged at the nosecone so they are parallel with the body of the rocket at launch. At the ejection charge, instead of popping off the nosecone, a piston pushes against the hinges, pushing the prop blades to 90 degrees versus the body tube, and then drag does the rest, and the body of the rocket simply spins downward for recovery. I'll upload some napkin drawings when I get a chance.

ESTES HELO-COPTER

 

[neil_w]

I am a fan of zero-prep tickets. I modified my Estes mini-A Heli to be zero-prep: https://www.rocketryforum.com/threads/mini-a-heli-modification-no-burn-string.164184/

Then there are saucers like the Estes Quinstar (just shove in a motor and go) and more unusual stuff like the Odd’l Cyclone (another one of my favorites).

Unfortunately, zero-prep rockets tend to be rare exceptions compared to the usual, but there are some options out there.

 

[Hobie1dog]

I have a Estes rocket that has three blades that come out with the nose cone and are supposed to be a helicopter separate from the air frame, but I see where they're supposedly rubber bands that are incorporated. But I do not know what size the rubber bands are?... maybe they are one used in dental work, anyone know?

 

[BABAR]

I).

Unfortunately, zero-prep rockets tend to be rare exceptions compared to the usual, but there are some options out there.

you should love @Dotini ‘s Horizontal Spin Rockets.

 

[CalebJ]

I have a Estes rocket that has three blades that come out with the nose cone and are supposed to be a helicopter separate from the air frame, but I see where they're supposedly rubber bands that are incorporated. But I do not know what size the rubber bands are?... maybe they are one used in dental work, anyone know?

Flip Flyer? I haven't tested it, but yes - dental bands have been mentioned in previous discussions as working perfectly.

 

[BABAR]

I have a Estes rocket that has three blades that come out with the nose cone and are supposed to be a helicopter separate from the air frame, but I see where they're supposedly rubber bands that are incorporated. But I do not know what size the rubber bands are?... maybe they are one used in dental work, anyone know?

I think they are the same size as these, pretty cheap at Wally World

https://www.walmart.com/ip/The-Beadery-Wonder-Loom-Rubber-Bands-600-Piece/36916178

 

[Hobie1dog]

Flip Flyer? I haven't tested it, but yes - dental bands have been mentioned in previous discussions as working perfectly.

I think it is called a "Hyper-X"

 

[Hobie1dog]

I think they are the same size as these, pretty cheap at Wally World

https://www.walmart.com/ip/The-Beadery-Wonder-Loom-Rubber-Bands-600-Piece/36916178

Thanks, I only need 3

 

[BABAR]

Always bring a few spares. Fecal Turbine interaction happens.