Candy cane rocket

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Nv7

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For Christmas we want to launch a candy cane rocket! However, I am not sure if it will work. I just want it to go mostly vertical and be safe.

CAD:
1700000288804.png
The nose cone is a very unconventional shape and I am not sure if it will fly correctly. To try to make it work, I put it into OpenRocket and entered all the mass correctly and made the stability 3.6. I know the side area of the nose cone will move the Cp up from what it is in the sims, reducing stability, and I believe having a higher stability is better to counteract the asymmetric forces on the nose cone. Do you think 3.6 stability is enough?
1700000398916.png

I will launch it with the Aerotech G80-10T. The main body tube is a PVC Pipe I got from home depot, and the adapter, fins, and nose cone will be 3d printed. The parachute will be an 18" parachute attached to the nose cone and the nose cone will be attached to the PVC pipe with some shock cord.

Will it be ok? Is there anything I need to change?
 
PSLimo said:
AMW's sold a 38mm candy cane rocket if your looking for design ideas.
Click to expand...
I remember watching a video of it, it didn't really look like a candy cane but I have the design completely fleshed out as you can see in the images, I'm just wondering if the stability margin is fine, if the nose cone will make it fly completely wrong, or if there's anything problematic like that. Especially because the center of gravity is no longer centered within the rocket, I don't know what will happen
 
Nv7 said:
For Christmas we want to launch a candy cane rocket! However, I am not sure if it will work. I just want it to go mostly vertical and be safe.

CAD:
View attachment 615490
The nose cone is a very unconventional shape and I am not sure if it will fly correctly. To try to make it work, I put it into OpenRocket and entered all the mass correctly and made the stability 3.6. I know the side area of the nose cone will move the Cp up from what it is in the sims, reducing stability, and I believe having a higher stability is better to counteract the asymmetric forces on the nose cone. Do you think 3.6 stability is enough?
View attachment 615493

I will launch it with the Aerotech G80-10T. The main body tube is a PVC Pipe I got from home depot, and the adapter, fins, and nose cone will be 3d printed. The parachute will be an 18" parachute attached to the nose cone and the nose cone will be attached to the PVC pipe with some shock cord.

Will it be ok? Is there anything I need to change?
Click to expand...
I can’t see how your simulated model is in anyway representative of the model you intend to fly. I don’t think you can rely on the simulated CG and CP in this case. The CG would also have a lateral offset and also asymmetric drag that would likely cause unstable flight.
 
Voyager1 said:
I can’t see how your simulated model is in anyway representative of the model you intend to fly. I don’t think you can rely on the simulated CG and CP in this case. The CG would also have a lateral offset and also asymmetric drag that would likely cause unstable flight.
Click to expand...
Yes I was worried about this, OpenRocket doesn't allow modeling it directly. I made the stability extra high to hopefully counteract this, do you think the stability will be ok? I explained my predictions for it in the original post
 
Nv7 said:
I remember watching a video of it, it didn't really look like a candy cane but I have the design completely fleshed out as you can see in the images, I'm just wondering if the stability margin is fine, if the nose cone will make it fly completely wrong, or if there's anything problematic like that. Especially because the center of gravity is no longer centered within the rocket, I don't know what will happen
Click to expand...

Here's a pic of the AMW Candy Cane rocket I was refering to:

candycane.jpg
 
Nv7 said:
Just the ones that are perpendicular to the nose cone? How do I calculate how much to cant it?
Click to expand...
I'm sure there are more technical and scientific ways, but basically it's not symmetrical, so both weight and drag are unevenly distributed along a few axes vs. your typical rocket.

One possible way to get close is to hang it upside down by the motor center next to a plumb line or vertical reference (like door edge) and mark the point in the curve which intersects, then angle the fins towards that point.

It gets more complicated when you try to factor in the element of one side of the top being open and having some base drag vs. the other side having a longer section angled in flight.

If you're going to test it, I'd recommend small first (mini engines).

This may be a good holiday build challenge that I may take up! :wavingsanta:
 
Pushing the asymmetric envelope will only lead you to the dark arts of mindsim. High powered oddrocs are an acquired taste. Start out with a smallish hook and big safety fins. Ditch the pvc and build light and strong like a proper Jedi. Learn the ways of the force. Your rocket not being really really good looking is not everything. After a time you can be seduced with forward mounted canted clusters to fly the hi po oddrocs you love. DO IT!
 
I asked some people and their main concern was the lack of a centered Center of Gravity. I added these mass objects which will bring the center of mass back inside and maybe cancel out the aerodynamic effects.

1700015105455.png
Thoughts on these? I cut out the area on the side to avoid affecting the center of pressure too much
 
Nv7 said:
I asked some people and their main concern was the lack of a centered Center of Gravity. I added these mass objects which will bring the center of mass back inside and maybe cancel out the aerodynamic effects.

View attachment 615523
Thoughts on these? I cut out the area on the side to avoid affecting the center of pressure too much
Click to expand...
I don't like them, they alter the purity. 😁

I'd try to find the CG, and cant both the motor mount and the side fins to point toward it.

The drag probably won't be perfectly symmetrical, but maybe close enough? A wind tunnel test would give me more confidence, if I could rig up a way for it to pivot on the CG when the CG isn't on the rocket.
 
Why not stick two or three canes together in a bundle? Put some easily lighting 29mm Estes F15's up front. Asymmetrical drag and stabilization problems suddenly disappear! Rear ejection would be cool . Nice smoke trail. Good igniters, clip whip if needed. Good power on ignition with good flying conditions. YIPPEE!

No no! Rockets need fins and a motor on the bottom of the rocket where they should be! Traditional design is best! Clustered, high powered, dark side oddrocs with widely spaced pods are dangerous. Do not be seduced. It's Christmas!
 
Nv7 said:
I asked some people and their main concern was the lack of a centered Center of Gravity. I added these mass objects which will bring the center of mass back inside and maybe cancel out the aerodynamic effects.

View attachment 615523
Thoughts on these? I cut out the area on the side to avoid affecting the center of pressure too much
Click to expand...
That could even be more of an RSO FRIGHTENING MACHINE!

Top end asymmetric drag off your thrust centerline really sucks!

20210807_100746.jpg
The Top Men may think you are a bit kooky.
 
Last edited:
Check out the new Bnb umbrella kit, he just posted it on Facebook. Fun with a D12 0! Could make an easy candy cane rocket with a different paint scheme.

BASE DRAG IS YOUR FRIEND!
 
Daddyisabar said:
Why not stick two or three canes together in a bundle? Put some easily lighting 29mm Estes F15's up front. Asymmetrical drag and stabilization problems suddenly disappear! Rear ejection would be cool . Nice smoke trail. Good igniters, clip whip if needed. Good power on ignition with good flying conditions. YIPPEE!

No no! Rockets need fins and a motor on the bottom of the rocket where they should be! Traditional design is best! Clustered, high powered, dark side oddrocs with widely spaced pods are dangerous. Do not be seduced. It's Christmas!
Click to expand...
I really want it to be a candy cane though :( Is there no way at all to make it work while looking like a candy cane? I could just make it a regular rocket but thats so boring, and 3 candy canes just looks weird.

I agree that the pods were a bad idea but even without them the Cg doesn't seem too bad:
1700023050838.png
As long as it doesn't go down towards us I'm fine with a curved flight. Would it go down with this or not?
1700023080341.png
 
Last edited:
Azamiryou said:
I don't like them, they alter the purity. 😁

I'd try to find the CG, and cant both the motor mount and the side fins to point toward it.

The drag probably won't be perfectly symmetrical, but maybe close enough? A wind tunnel test would give me more confidence, if I could rig up a way for it to pivot on the CG when the CG isn't on the rocket.
Click to expand...
It is in the tube, just on the side of it. I could try tilting the fins 1 or 2 degrees, I agree that the pods make it ugly
1700025151984.png
 
Last edited:
Nv7 said:
It is in the tube, just on the side of it. I could try tilting the fins 1 or 2 degrees, I agree that the pods make it ugly
View attachment 615530
Click to expand...
You could, but the optimum fin angle is at best a guess. You also need to account for asymmetric drag. Another guess! You might improve you chances of success (?) by reducing the radius of curvature of the hook and bringing the asymmetric ‘nosecone’ closer to the main body axis.

I would be launching this from a far pad just to be safe - even on a G80.
 
Last edited:
lakeroadster said:
My mindsim says nearly vertical flight. cg is just a hair off the main centerline.

Kick a tire... and light the fire.
Click to expand...
Trust the Lakeroadster mindsim! He can go to that place the Bene Gesserit fear.

This rocket reminds of the good ole days when our old RSO would yell out "No crooked rockets!"

Bob Uecker in Major League: "JUST A BIT OUTSIDE!"

Launching an extreme candy cane: "CG JUST A HAIR OFF THRUST CENTERLINE!"

Yes, looking good is the most important. Trust your feelings. Use the Force. Launch the rockets you love. Keep your knees bent, eyes on the prize and ready to run! :)
 
Nv7 said:
I really want it to be a candy cane though :( Is there no way at all to make it work while looking like a candy cane? I could just make it a regular rocket but thats so boring, and 3 candy canes just looks weird.

I agree that the pods were a bad idea but even without them the Cg doesn't seem too bad:
View attachment 615527
As long as it doesn't go down towards us I'm fine with a curved flight. Would it go down with this or not?
View attachment 615528
Click to expand...
Its not all about having the CG way up there for stability. All that extreme off axis drag, especially up top is a problem. Could lead to a curved flight in your direction, especially with any breeze.

Little hook, big fins or base drag...Good.

Big hook, little fins...Not so Good.

The drag offset idea is ok, just a bit scary from being funny looking.
 
A cute little fin on the other side of the curve? Maybe shaped and painted like an Elf waiving at the crowd, ready to go for a ride?

Yes Mr. RSO, Fins up front are cool and this cute little Elf fin will balance drag up front. Makes it much more safe. AND THE LADIES AT THE LAUNCH REALLY DIG IT! Looking good for the ladies is TIGHT! ;)
 
Nv7 said:
For Christmas we want to launch a candy cane rocket! However, I am not sure if it will work. I just want it to go mostly vertical and be safe.

CAD:
View attachment 615490
The nose cone is a very unconventional shape and I am not sure if it will fly correctly. To try to make it work, I put it into OpenRocket and entered all the mass correctly and made the stability 3.6. I know the side area of the nose cone will move the Cp up from what it is in the sims, reducing stability, and I believe having a higher stability is better to counteract the asymmetric forces on the nose cone. Do you think 3.6 stability is enough?
View attachment 615493

I will launch it with the Aerotech G80-10T. The main body tube is a PVC Pipe I got from home depot, and the adapter, fins, and nose cone will be 3d printed. The parachute will be an 18" parachute attached to the nose cone and the nose cone will be attached to the PVC pipe with some shock cord.

Will it be ok? Is there anything I need to change?
Click to expand...
Just an idea. What if you flipped the crook of the cane around to the tail added to more and make them fins. When you do the paint you could make it look like it was licked into a point like we used to do when we were kids.
 
lakeroadster said:
Point the C/L of the motor through the CG of the "all up rocket" (The front centering ring needs the I.D. hole offset from the O.D. hole.)
Click to expand...
Wow. This is some high end science, way beyond my grade level. But I really want to see this work!

I thought you were to set the thust centerline angle to halfway between the CP and CG. It was in one of the Apogee papers. Who knows?

Canted motors, fins, advanced airflow through precisely placed holes! Give me some GDS to top it off! Blind me with Science!

Yes, Santa. You really can fly the extreme Candy Cane rocket you love! :)
 

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