modularity and maintenance

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watermelonman

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I have now seen more than a few fantastic rockets and builds, where I love the craftsmanship but cannot help think the build gets in the way of future possibilities. For example, having a ton of electronics embedded in the belly of a fiberglass rocket. One can easily add external connectors for readings and firmware updates, but what about more significant maintenance? Even in simple and low power builds I have asked myself what I could do if I needed to replace a shock cord tied down low in a narrow tube, or if any aspect of the motor mount area and through wall fins needed replacement.

Until now I have simply accepted that my builds are temporary and somewhat disposable, but there has to be a better way! What kind of techniques or methods could you envision to improve modularity and maintenance?
 
You're just going through typical newbieee ......newness....faze.

Overthinking possible future builds, & worrying too much. Glue Kevlar to the motor mount .[appropriate size of course for the rocket] if you screw it up, glue another to a section of coupler....slide down around MM and ready to go again.............next?

Start flying them like you don't care, & they will always come back.

Just stick an altimeter in the bay, when done ya have to take it apart anyway to clean & re-prep. Just leave the alt. on the sled, hook up to comp or LCD & be on your way.

Less is always "MO beta"

Build a couple test mules & don't even paint them, just fly 'em till they puke. You will be surprised how long, and how much punishment they will take to kill.

It has to be fun...........!
 
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Even in simple and low power builds I have asked myself what I could do if I needed to replace a shock cord tied down low in a narrow tube, or if any aspect of the motor mount area and through wall fins needed replacement.
Until now I have simply accepted that my builds are temporary and somewhat disposable, but there has to be a better way! What kind of techniques or methods could you envision to improve modularity and maintenance?

I came up with a replaceable Kevlar mount for LPR models. You can check the area most exposed
to the ejection charge and replace your Kevlar if needed. It's best described in the Apogee POF article:
https://www.apogeerockets.com/education/downloads/Newsletter338.pdf

You're right, rockets don't last forever. Well built models will last longer.
 
A lot of the approach depends on which part of the hobby you like. Is building a rocket the goal itself or is the goal just to have a vehicle in which to install motors?

For those who just want a vehicle to fly motors, then I think cheap/easily replaceable is a better route than complex/repairable. Ari Krupnik has done some fantastic work with his tube-fin rockets in this area, even flying an M motor in a rocket assembled with phenolic tube and wood glue.
 
Hi there!

Some will call me the king of modular rocket building. All of my high power rockets are modular in design. Something happens, repair / replace the module(s) with the damage, slap it back together, and its as if nothing happened.

I'd recommend this method (as someone said before) if you get your rocks off on engineering rockets....which I do. The flight is the icing on the cake. It does make the build exponentially more complex than the equivalent "simple build" design. If you just want to fly & have fun, don't even think about modular. If you like to tinker, engineer, etc. you'll probably find it fun.

It takes time, and a lot of patience to come up with a modular design that will hold together under the stresses of flight, and maintain air pressure integrity...you don;t want the ejection gasses to escape anywhere except where they are supposed to! This makes modular designs challenging. WHen you get it done, there is nothing like the feeling of seeing a highly engineered rocket fly & function as designed. :)

Attached are pics of my Nesaru rocket on the pad. Each segment is pretty obvious due to the color pattern changes... The second pic is the rocket broken down to its modules. The modular design also makes replacing worn out baffles & repairing fin damage a snap. Again, this convenience comes after a lot of sweat designing & building...

Nesaru_on_pad.jpgNesaru_Cleanup.jpgNLS-005_liftoff_desktop.jpg
 
If you make something bulletproof the first time, there is no need to worry about maintenance.

For structures like fin cans, tat I know I only have one shot at building, I try to make it as indestructible as possible.
 
Hi there!

Some will call me the king of modular rocket building. All of my high power rockets are modular in design. Something happens, repair / replace the module(s) with the damage, slap it back together, and its as if nothing happened.

I'd recommend this method (as someone said before) if you get your rocks off on engineering rockets....which I do. The flight is the icing on the cake. It does make the build exponentially more complex than the equivalent "simple build" design. If you just want to fly & have fun, don't even think about modular. If you like to tinker, engineer, etc. you'll probably find it fun.

It takes time, and a lot of patience to come up with a modular design that will hold together under the stresses of flight, and maintain air pressure integrity...you don;t want the ejection gasses to escape anywhere except where they are supposed to! This makes modular designs challenging. WHen you get it done, there is nothing like the feeling of seeing a highly engineered rocket fly & function as designed. :)

Attached are pics of my Nesaru rocket on the pad. Each segment is pretty obvious due to the color pattern changes... The second pic is the rocket broken down to its modules. The modular design also makes replacing worn out baffles & repairing fin damage a snap. Again, this convenience comes after a lot of sweat designing & building...

View attachment 247381View attachment 247382View attachment 247383

Man, that's pretty hard core Cornelius! You could probably dedicate an episode to modular design; I'd be listening.....
 
If you make something bulletproof the first time, there is no need to worry about maintenance.

For structures like fin cans, tat I know I only have one shot at building, I try to make it as indestructible as possible.

That's one line of thinking.

Personally, if something goes really wrong, I'd rather have to make repairs to the rocket to replace sections designed to destroy themselves vs. catastrophic damage to anything on the ground...

Another aspect to the modular design is that I can easily change the design without building an entirely new rocket. Want to try a different fin configuration? Build a new fin can & bolt it on!

There are a multitude of reasons I went modular. Repairing broken fins was just one out of many, many reasons.

If you look at what I do from the perspective of simply shooting a rocket up, recovering, and flying again, none of what I do makes any sense. But that is not what I do. my rockets are research projects, and the designs will need to be changed & adapted to different scenarios...and that does happen.

Modular design works best for me, and I wouldn't trade it for anything...but it is not for the faint of heart...

-C
 
Keep it to a minimum. The more steps to assemble a rocket the more mistakes can be made.
My L3 Breaks down into 4 (5 if you count the nose cone separately) sections and it's 12 ft tall!

JD
 
Man, that's pretty hard core Cornelius! You could probably dedicate an episode to modular design; I'd be listening.....

LOL...

I'd think a video podcast on the way these rockets are designed & built would be way easier than trying to describe all of that in words. LOL. I am working on some ideas for occasional special video podcasts for subjects that work best with video. This could be one topic. A lot of people think what I do is cool, but the vast majority have no real use for building rockets this way other than for the coolness factor.

Modularity tricky to do without making the rocket really heavy (the one I showed in the pics is pretty heavy). I have new construction & design techniques that is still modular, but considerably lighter. The margins on that are so much tighter. No room for error when something modular is that optimized. But she sure flies nicely. Pic of that rocket lifting off is attached.

This rockets does not break down into as many sections as the other rocket (Nesaru), but she can be fully disassembled as well. Modularity is obtained mostly by being able to remove all of the internal parts ... fin can, baffles, etc. from the outside frame. Frame bolts together in three sections. Nesaru is my first fully modular rocket, and was completed 2 1/2 years ago. Comanche is the young pup, sporting everything I've learned from the first one.

Comanche_CLS-005_RF.jpg

-C
 
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Keep it to a minimum. The more steps to assemble a rocket the more mistakes can be made.
My L3 Breaks down into 4 (5 if you count the nose cone separately) sections and it's 12 ft tall!

JD

So true!

For me, it's part of the challenge. Prepping the rocket keeps me on my toes. ;-) Comanche is much easier to fly...the way the modular design was done in that one, it makes it easier to prep for dual deploy (faster turn around). Put that to the test last May. Three flights in one afternoon. That's a record for me on a dual deploy!

:)

My caveats on this kind of construction still apply. As do yours!!!

-C
 
I should point out that I do not routinely fully dis-assemble the rockets between flights. Unless there is a reason to go in before, they are only fully dis-assembled a couple of times a year to inspect things, and do a really good cleaning of the guts...

Otherwise, they dis-assemble (for the most part) the same as any other dual deploy

-C
 
LOL...

I'd think a video podcast on the way these rockets are designed & built would be way easier than trying to describe all of that in words. LOL. I am working on some ideas for occasional special video podcasts for subjects that work best with video. This could be one topic. A lot of people think what I do is cool, but the vast majority have no real use for building rockets this way other than for the coolness factor.

Modularity tricky to do without making the rocket really heavy (the one I showed in the pics is pretty heavy). I have new construction & design techniques that is still modular, but considerably lighter. The margins on that are so much tighter. No room for error when something modular is that optimized. But she sure flies nicely. Pic of that rocket lifting off is attached.

This rockets does not break down into as many sections as the other rocket (Nesaru), but she can be fully disassembled as well. Modularity is obtained mostly by being able to remove all of the internal parts ... fin can, baffles, etc. from the outside frame. Frame bolts together in three sections. Nesaru is my first fully modular rocket, and was completed 2 1/2 years ago. Comanche is the young pup, sporting everything I've learned from the first one.

View attachment 247409

-C

I'm super impressed Cornelius. I must admit I haven't given modular rockets any thought but after seeing your stuff it's got me to thinking....
 
You're just going through typical newbieee ......newness....faze.

Overthinking possible future builds, & worrying too much. Glue Kevlar to the motor mount .[appropriate size of course for the rocket] if you screw it up, glue another to a section of coupler....slide down around MM and ready to go again.............next?

Start flying them like you don't care, & they will always come back.

Just stick an altimeter in the bay, when done ya have to take it apart anyway to clean & re-prep. Just leave the alt. on the sled, hook up to comp or LCD & be on your way.

Less is always "MO beta"

Build a couple test mules & don't even paint them, just fly 'em till they puke. You will be surprised how long, and how much punishment they will take to kill.

It has to be fun...........!

Oh believe me, it does not come from being new or some kind of obsession with sustainability despite the reputation of my home state! The ones I built as a kid, I did not think much about it at the time but looking back when they had easily replaced shock cords or parachutes they saw a lot more flight and versatility. I get that most rockets are relatively cheap and building them is certainly a big part of the fun, but there can be a balance. Check out the build that motivated me to bring this up -
https://www.rocketryforum.com/showthread.php?66425-L3-Build-Spikey

Especially this, and a comment from Feckless Counsel about entombing it all in fiberglass -
https://www.rocketryforum.com/attachment.php?attachmentid=174232&d=1402267702

It looks so awesome! Nothing but respect for the Random Flying Object and his decisions, but I would want to be able to get back in there. Heck even my low power builds I have wanted to get back into the fin box or body tube near motor top, although most of the time there getting a hand or tool that deep is the limitation.

Anyway, I wanted to see what other people had done or thought. I am happy to have found that shock cord mount from hcmbanjo, and I will certainly be following posts from cgould in the future! I have definitely spoken to Ari about his L3 rocket too.

Thanks all!
 
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