I made a big and light boattail.

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Are your fins foam too? If they are, be prepared to replace them... often. The boattail looks great. Let us know how it flies.
 
Are your fins foam too? If they are, be prepared to replace them... often. The boattail looks great. Let us know how it flies.

Thanks for your advice.
However, since the fin base strengthens the structure, it needs to be firmly bonded to the ring and outer shell.
If the fin breaks, the entire tail part must be recreated.
The state of the launch is in a past blog.
After several launches, the fins have not broken yet.

https://gallery-h.net/top/?p=415
 
Similar to the technique I published in Apogee's newsletters 409 & 410...I like the choice of materials for this lightweight cone! More sections will provide a smoother outline. You can use OR to create those transition flat wraps.

https://www.apogeerockets.com/education/downloads/Newsletter409.pdf
https://www.apogeerockets.com/education/downloads/Newsletter410.pdf

Certainly it is very similar.
I calculated with Calc of googleDrive and plotted with Inkscape.
The files used are published on GoogleDrive.

https://drive.google.com/drive/folders/1wSAcZrGA4emgHsygmeCurVlRYc56Ang0
 
That’s a nice design! You did a good job with it. I made a very lightweight rocket using a similar technique a few years ago. I used polystyrene foam board for centering rings and made a skin for the rocket using paper card-stock. I was able to make a rocket that was large in size but still very lightweight. Your technique and craftsmanship is more advanced than mine was, but it’s the same basic idea.
 
That’s a nice design! You did a good job with it. I made a very lightweight rocket using a similar technique a few years ago. I used polystyrene foam board for centering rings and made a skin for the rocket using paper card-stock. I was able to make a rocket that was large in size but still very lightweight. Your technique and craftsmanship is more advanced than mine was, but it’s the same basic idea.

I will challenge the contest to launch the largest rocket as high as 40m.

https://translate.weblio.jp/web/english?lp=&url=https://spc.uematsudenki.com/index.php/ja/mn-rocket.html&sentenceStyle=spoken

That's why I need a big and light rocket.
I don't know how to make a lighter boattail.
 
I will challenge the contest to launch the largest rocket as high as 40m.

https://translate.weblio.jp/web/english?lp=&url=https://spc.uematsudenki.com/index.php/ja/mn-rocket.html&sentenceStyle=spoken

That's why I need a big and light rocket.
I don't know how to make a lighter boattail.

That is an interesting contest!

What is the rocket motor that is being used for the contest?

There are a lot of variables to consider for this kind of contest! The one constant for all contestants will be the motor, so I think your plan must start with the motor. For a given motor, the altitude will depend on both mass and aerodynamic drag. Drag will be affected by the diameter and other factors, like your boat tail. And volume and mass will be affected by diameter too. This is an interesting and complicated problem! Good luck!
 
That’s a nice design! You did a good job with it. I made a very lightweight rocket using a similar technique a few years ago. I used polystyrene foam board for centering rings and made a skin for the rocket using paper card-stock. I was able to make a rocket that was large in size but still very lightweight. Your technique and craftsmanship is more advanced than mine was, but it’s the same basic idea.

Links? It's 3 AM... I donwannalookiupmuself
 
That’s a nice design! You did a good job with it. I made a very lightweight rocket using a similar technique a few years ago. I used polystyrene foam board for centering rings and made a skin for the rocket using paper card-stock. I was able to make a rocket that was large in size but still very lightweight. Your technique and craftsmanship is more advanced than mine was, but it’s the same basic idea.
It's almost 3:30am local... How about some links? I'm too tired to hunt for them on my own.
 
Links? It's 3 AM... I donwannalookiupmuself

Ok, lazy-butt! ;)

Here is a link to a long thread about building large lightweight rockets. The build of the rocket I mentioned with foam rings and cardstock skin is near the end. https://www.rocketryforum.com/threads/low-mass-high-drag-designs.132002/

Here is a thread about another rocket I built that is also very lightweight for its size, but it’s a lot denser and more robust than the other one, so the technique is probably not great for the purposes of this contest. This one is for high-power motors. Next motor will be I class, and eventually I may fly it on a J. I’m also hoping to do air starts. https://www.rocketryforum.com/threads/big-lightweight-rocket-made-of-rigid-foam-insulation.152412/
 
I'm hating my connection with the internet... The 3 AM post looked like it didn't post, so I posted the 3:30 AM post... Now both appear... Damn, will I need to do this again at 5:45 AM?
 
I'm hating my connection with the internet... The 3 AM post looked like it didn't post, so I posted the 3:30 AM post... Now both appear... Damn, will I need to do this again at 5:45 AM?

I’m seeing your posts, and I replied just now, and then edited my post with a second link. Are you seeing my reply? Of course, if not, then you are probably not seeing this post either...
 
That is an interesting contest!

What is the rocket motor that is being used for the contest?

There are a lot of variables to consider for this kind of contest! The one constant for all contestants will be the motor, so I think your plan must start with the motor. For a given motor, the altitude will depend on both mass and aerodynamic drag. Drag will be affected by the diameter and other factors, like your boat tail. And volume and mass will be affected by diameter too. This is an interesting and complicated problem! Good luck!

I am making it to launch the rocket with a B6-4 motor.
In order to fly 40m, it must be kept under 70g.
If they are made with the same weight, the thicker and shorter the volume becomes.
Among them, the diameter was 114mm and the total height was 1500mm as a size that was easy to make and stable launch.
 
Back
Top