An "R"-powered rocket build

[Rail Dawg]

Going to start a new thread on this.

We've got a 9" diameter 7 1/2' long "Q" motor casing that's going to need a rocket.

Our biggest concerns off the bat are transferring the power of the motor to the rocket and what type of fins we'll need.

Can multiple G-10 layers be glued together to create a strong fin? Of course they would then be carbon-fibered tip-to-tip. We've been reading other ideas centering around a foam or balsa core. Just wondering if the ease of multiple layers of G-10 would work. Heavy yes but perhaps not prohibitively so.

We're going to throw out ideas and if they are bad ideas just say so and we'll adjust.

Thanks.

Here's the motor casing for those that haven't seen it yet:

 

[BDB]

I'll be following this thread intently. Good luck!

 

[AeroAggie]

This looks like an awesome project and I love the crowdsourcing approach, but I think you'd get a lot more meaningful, constructive feedback if you were to start with some basic design parameters to bound the problem. Throw an OpenRocket or RockSim sketch together and get some estimates on weight, speed, etc.

 

[3stoogesrocketry]

I would make a aluminum fin can . I would make a 9.5 inch OD fin can with some 1/4 inch t6 plate cut to shape , welded to the fin can . This would weigh the most , but easiest to manufacture. If you want composite , I would start with 1/4 inch phenolic plate glued to a composite tube , then 5 or 6 good layer of carbon vacume bagged tip to tip. Your fin can construction will depend on how hard and fast your motor will burn . To do it right , you need to have a working motor to design the rocket around.

Eric

 

[CzTeacherMan]

Following out of raw curiosity. Are you looking for a minimal rocket, or just some bigass monster rocket that'll hold up? That's a huge difference. I could see this motor in something like a full scale Patriot...

 

[mpitfield]

Did the 6 fire extinguishers, in the background, come with the motor case. I would strap some aluminum fins directly to the case and do a sub-min diameter Q...sounds so appealing to me!

Do you have a thrust curve graphed for that motor?

 

[Rail Dawg]

This looks like an awesome project and I love the crowdsourcing approach, but I think you'd get a lot more meaningful, constructive feedback if you were to start with some basic design parameters to bound the problem. Throw an OpenRocket or RockSim sketch together and get some estimates on weight, speed, etc.

Good points.

The one thing we want is a robust rocket. G-12 fiberglass as the airframe is easy to do but unfortunately it's only affordable up to the 12" size. G-12 can be had even up to 24" and higher but that gets very expensive very quickly.

Eric above mentions an aluminum fin can and that is something we'd like to explore.

Of course we then are talking almost a minimum-diameter rocket that is going to perhaps go much faster than we'd like.

Am working on RockSim as we speak but don't have enough together to put it out quite yet.

Definitely at the design stage but that is where we want to bring in the collective talent. Have learned long ago the group ALWAYS comes up with better decisions than the individual.

If we go with a much larger airframe I'm guessing cardboard wrapped in fiberglass or carbon. Not a bad choice but we'd prefer the G-12.

Listening.

 

[Rail Dawg]

Did the 6 fire extinguishers, in the background, come with the motor case. I would strap some aluminum fins directly to the case and do a sub-min diameter Q...sounds so appealing to me!

Do you have a thrust curve graphed for that motor?

Many of you might recognize the name Pat Gordzelik. He is the the man in charge of the motor construction. You can't ask for a more knowledgeable and people-friendly person to have on a project such as this.

Just gave him the casing/nozzle parameters and once he crunches the numbers we'll have an idea of what this thing will put out.

I'm going to be with him during the motor-build process as I'd like to be able to pour a "Q" motor of my own one day.

We plan on building one and test it out at his ranch and then build another for the launch.

 

[Rail Dawg]

Following out of raw curiosity. Are you looking for a minimal rocket, or just some bigass monster rocket that'll hold up? That's a huge difference. I could see this motor in something like a full scale Patriot...

I like the idea of a full-scale Patriot but I assume the only option is cardboard and fiberglass/carbon right?

Originally the thought was a large diameter, heavy rocket but for simplicity sake it seems the 12" G-12 might be the material.

Of course then we are talking about a very fast, altitude-busting rocket.

Still considering the design.

 

[Rail Dawg]

Looking at various pre-made airframes in the 24"+ range.

There's quite a few fiberglass tubes obviously used for other purposes that might just fit the bill.

The advantages of using 12" are parts like nose cones are readily available.

 

[dhbarr]

A quick sketch with around 30cm comes in at about 10kft on 30kNs and m~0.8.

If you want to see the whole thing fat is the way to go.

 

[llickteig1]

A quick sketch with around 30cm comes in at about 10kft on 30kNs and m~0.8.

If you want to see the whole thing fat is the way to go.

???
Q impulse 81,920–163,840 Ns

We did 62,000+ Ns in s 30" Sonotube, fiberglass skinned airframe and phenolic honeycomb core 1" fins with fiberglass skins. 3/4" nine-ply bulkheads and plywood internal structure to hold the motors. We hit pretty hard off the pad with a central baby P and 3 high thrust Ms. Nebraska team has built a number of wooden frame with cardboard/fiberglass skins P & Q birds.

We have seen foam core fins fail on big rockets. You can do G10 but weight aft is bad. We cut a lot of lightening holes in internal structure to reduce weight aft. Big nosecones aren't terribly tough. Dan Schwartz of Python Rocketry was doing custom large nosecones. Ask Pat G, he has made a few.

Good luck. It's fun.

 

[dhbarr]

Was just what I could throw together quickly to check my assumptions

 

[DAllen]

GOOD GOOGLY MOOGLY

(subscribes to thread)

 

[djs]

We've got a 9" diameter 7 1/2' long "Q" motor casing that's going to need a rocket.

Well, you do have that refrigerator in the background that you could use.

Where/when do you plan on flying this?

 

[BDB]

Well, you do have that refrigerator in the background that you could use.

Now that's a plan!

 

[Bat-mite]

Get in touch with user Scott S, who made the Q motor for last year's record-breaking Mercury Redstone launch. He has made two Q motors, and I'll bet he has lots of wisdom to share. Good luck with your project!

 

[tomsteve]

you might be able to get some contruction info from the thread on the 3/4 restone bat-mite mentioned:
https://www.rocketryforum.com/threads/3-4-mercury-redstone.130444/

 

[Rail Dawg]

you might be able to get some contruction info from the thread on the 3/4 rest-one bat-mite mentioned:
https://www.rocketryforum.com/threads/3-4-mercury-redstone.130444/

Thanks for that!

Chuck

 

[Rail Dawg]

Get in touch with user Scott S, who made the Q motor for last year's record-breaking Mercury Redstone launch. He has made two Q motors, and I'll bet he has lots of wisdom to share. Good luck with your project!

Good info. Thanks!

Chuck

 

[Rail Dawg]

Well, you do have that refrigerator in the background that you could use.

Where/when do you plan on flying this?

Next years BALLS is the plan!

Would like to learn more about building a large nosecone if I go bigger than 12”.

Any custom builders of these out there?

Chuck

 

[Rail Dawg]

???
Q impulse 81,920–163,840 Ns

We did 62,000+ Ns in s 30" Sonotube, fiberglass skinned airframe and phenolic honeycomb core 1" fins with fiberglass skins. 3/4" nine-ply bulkheads and plywood internal structure to hold the motors. We hit pretty hard off the pad with a central baby P and 3 high thrust Ms. Nebraska team has built a number of wooden frame with cardboard/fiberglass skins P & Q birds.

We have seen foam core fins fail on big rockets. You can do G10 but weight aft is bad. We cut a lot of lightening holes in internal structure to reduce weight aft. Big nosecones aren't terribly tough. Dan Schwartz of Python Rocketry was doing custom large nosecones. Ask Pat G, he has made a few.

Good luck. It's fun.

This is great info!

Thanks.

Chuck

 

[Rail Dawg]

Let me ask about the 30” sonotube.

That’s not a bad idea.

How did you do the couplers? Was it dual-deploy?

Shooting from the hip I wonder if we could not go for the complexity of dual deploy and simply blow the mains at altitude. At Black Rock there’s miles and miles of recovery room.

Only problem would be if the thing got cockeyed and the mains were blown at high speed.

Chuck

 

[ThirstyBarbarian]

GOOD GOOGLY MOOGLY

(subscribes to thread)

Madre de Dios!

(also subscribes to thread)

 

[ThirstyBarbarian]

Let me ask about the 30” sonotube.

That’s not a bad idea.

How did you do the couplers? Was it dual-deploy?

Shooting from the hip I wonder if we could not go for the complexity of dual deploy and simply blow the mains at altitude. At Black Rock there’s miles and miles of recovery room.

Only problem would be if the thing got cockeyed and the mains were blown at high speed.

Chuck

Maybe you could use a Jolly Logic Chute Release and a very long rubber band.

This project is amazing to me. Very cool to see a motor larger than my largest rocket! If you flight it at BALLS, maybe I'll finally brave the playa and go out there.

If it were my project, I'd be headed in exactly this direction with a very high-diameter tube such as the 30" sonotube. Bigger, not higher!

For extra large nosecones (or even entire giant rocket airframes) I've been intrigued by the ones that use styrofoam cut with a hot wire foam cutter and then laminated with fiberglass. I'm trying to find the site where the technique was detailed, but can't seem to find it now. IIRC, it was some brothers who made very large-scale sic-fi rockets, but the technique could also be used for just making a very large cone.

 

[Rail Dawg]

Q impulse 81,920–163,840 Ns

What was the loaded weight on this motor?

Thanks.

Chuck

 

[BDB]

The best source for giant nosecones is Python Rocketry, but I think the owner has been ill lately. I've recently become interested in this method for creating a FG nosecone using foam board.

 

[Bat-mite]

For his Yellow Submarine ( https://www.google.com/url?sa=t&rct...=U6aIiI3ZjKs&usg=AOvVaw3QKR-i1RAJpLadZroiGJsR ), Tom C. had a custom NC built by Python Rocketry (don't know his health status, may not be in business). His fins were made of 1-inch foam with multiple layers of FG wrap. AV bay was built with wood, as were the CRs and inner structure. Pad weight was over 600 lbs. Flew on a measly O motor.

I can get you in touch with the builders of the 3/4 scale Mercury Redstone, Scott S., and Tom C. if you PM me your contact info.

 

[Rail Dawg]

Is there anyone out there willing to be a Design Engineer on this project?

My RockSim/Open Rocket skills aren’t proficient enough to do as good a job as necessary. Like all of you I love aerodynamics but a man must know his limitations.

If one or a few of you are willing you’ll get the credit lol. Just be ready for design changes especially in the beginning.

Any large project simply can’t be done correctly by just one person.

 

[CzTeacherMan]

Maybe you could use a Jolly Logic Chute Release and a very long rubber band.

This project is amazing to me. Very cool to see a motor larger than my largest rocket! If you flight it at BALLS, maybe I'll finally brave the playa and go out there.

If it were my project, I'd be headed in exactly this direction with a very high-diameter tube such as the 30" sonotube. Bigger, not higher!

For extra large nosecones (or even entire giant rocket airframes) I've been intrigued by the ones that use styrofoam cut with a hot wire foam cutter and then laminated with fiberglass. I'm trying to find the site where the technique was detailed, but can't seem to find it now. IIRC, it was some brothers who made very large-scale sic-fi rockets, but the technique could also be used for just making a very large cone.

The Jolly Logic actually isn't a terrible idea... You could actually use it to reef the chute. Hell, you could use a series of them to systemically deploy the chute every 100-200 feet.