How to make a model rocket fly higher?

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Kirra Labas

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I'm still new here, and it's a pleasure to meet you all!​

If it's not too much of a bother, I like to get some advice on making a model rocket kit fly higher. Like a few general tips that can be used before/during launch. Or maybe some slight modifications that can be made to a model rocket.
 

teepot

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You can reduce the drag by sanding an airfoil on your fins. A slick surface will reduce drag. Smaller diameter tubes have less drag than large tubes.
 

prfesser

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Drag is probably your biggest enemy.

Be sure that fins are absolutely square to the tube, aligned with the tube axis, and spaced properly.

Fill-and-sand-and-fill-and-sand-and-fill.... There are several posts on how to fill the spirals of a paper tube easily and efficiently. Balsa should be filled until no grain is visible. Most people on this forum use Elmers Fill-and-finish, thinned with water slightly to a creamy consistency. It's cheap and it works. "spot putty" from the automotive store is more expensive but dries MUCH faster. Thin with acetone as needed. Use it outside if you do not want your mother/father/wife/significant other to perform unwanted surgery on you... :)

Prime, paint, sand (very fine sandpaper) to a super-slick finish. I think some have used paste wax for a better shine. Others on this list will undoubtedly give good advice on how to get that finish.

A fly-away launch lug instead of gluing will improve altitude, there's a fair bit of drag on a launch lug.

IF you don't mind minor alterations and IF the motor mount tube extends back of the main airframe, a cardstock tailcone may help.

I'm tapped out now. Anyone else?

Best -- Terry
 

dr wogz

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Which kit / rocket are we talking about? Some kits are designed to go high, while others are designed to 'look cool'..

Sim it to optimize it.

Depending on the kit, sometimes a little more weight adds to the overall altitude (inertia in the model)
Look at your motor choices, sometimes a long steady push is better than an initial short & powerful 'whack'! (but I( assume you are limited to "Estes" motors..)
Look at body length. Reduce all your surfaces to the absolute minimum to reduce your overall drag.
Go minimum diameter. A 3" tube & nosecone has more frontal area than a 1" tube & nosecone.. the 1" dia rocket will have less resistance going up..
 

David Schwantz

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Dr is correct. Add weight to the rocket. if you have a sim program, run it with a mass in the NC. Keep adding until you lose altitude and then go back to last known weight and add that to NC. After burnout the correct mass will keep the rocket moving, it is called momentum. :)
 

mjennings

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Also why are you chasing altitude? Contest building, record setting, etc?
Higher flight means longer recovery unless non engine ejection change recovery deployment is used, (chute release, dual deploy, etc) which will add weight and rob altitude.
 

neil_w

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Dr is correct. Add weight to the rocket. if you have a sim program, run it with a mass in the NC. Keep adding until you lose altitude and then go back to last known weight and add that to NC. After burnout the correct mass will keep the rocket moving, it is called momentum. :)
OpenRocket will do this for you in Tools -> Rocket Optimization
1619213255072.png

You can also optimize length and other things. Basically it just iterates on within a specified range of values, and tells you the value that produces the highest optimized value (which is usually Apogee altitude, as shown above).

Ultimately, drag is probably your biggest enemy.
 

David Schwantz

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Also why are you chasing altitude? Contest building, record setting, etc?
Higher flight means longer recovery unless non engine ejection change recovery deployment is used, (chute release, dual deploy, etc) which will add weight and rob altitude.
Not always true. Go Devil, 29mm, I205 sent her just under 10'000 agl. Motor eject, streamer, came down about 50' in front of flight line.
 

GalantVR41062

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A lot of good information. Open Rocket, Rocksim and a lot of time will help optimize a rocket and flight profile.

There is something to be said about getting out and actually flying and recovering rockets. Keep a log book of the rocket, flights, weather conditions.

Learn how to fly your field. If you send your prized altitude seeking project into the great blue sky never to be seen again by you then what's the point?

More Newton seconds and minimized hole your trying to push up is the name of the game.

If you choose a fast burning high average thrust motor, then having a little more weight for momentum or inertia will help with the rocket in the coast phase of the flight.

If you are using a long burn low average impulse motor then having the least amount of weight should net the highest altitude.

The advanced rocket will be multi stage rocket projects but has a new set of flight challenges.

Electronics: flight computers and or altimeters to help with dual.deploy, cable cutters, recording the flight parameters, tracking devices to help find the project.

Build the rocket to withstand the flight profile and stay together on the up part and survive the landing.

~John
 

kuririn

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mjennings

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Not always true. Go Devil, 29mm, I205 sent her just under 10'000 agl. Motor eject, streamer, came down about 50' in front of flight line.
Sure it happens that a high flight lands close to the pad. But when I was flying with folks and we had a 10k waiver close to the pad was the exception.
 

David Schwantz

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Sorry m, but we have a 19k waiver. For the most part we land on the field. We have drainage ditches all around, sucks getting them out. Damn, I've seen a couple flights hit the pad on landing :)
 

Kirra Labas

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Everyone, thank you for your answers.
I now have some idea of what to do. By the way, can you tell me what model rocket boosters are? And is it something that can help the rocket fly higher?
 

David Schwantz

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Booster is the lower part of the airframe. As opposed to the payload section, which is the upper part right behind the NC.
 

BABAR

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Paradoxically “getting” your rockets to fly higher may conflict with “proving” your rockets fly higher.

although you can still go old school and get one of these trigonometric altitude measuring tools,
https://estesrockets.com/product/002226-mini-altitrak-altitude-tracker/. I haven’t seen one actually used.

Most people now that are altitude seekers get altimeters. These add a little mass to the rockets, that can be good or bad. With these, when properly used, you can keep track to what the rocket actually did.

Are you trying to get the most altitude out of each rocket you fly (or for a given motor size), or are you simply someone that wants to fly high.

if the former, you are building competition style, so all the above suggesting (air-foiled fins with rounded front and taper [and easily broken] trail edges, smooth finished (but light), optimized fin size as length and nose cone, ditch the lug an get a tower with a piston launcher, it can get pretty crazy.

if the latter (“I just want to send it waaaaaaay up there!”) then go for something minimum diameter that takes a G motor (beyond that mostly you are looking at high power, need a certification and can only fly with FAA waiver.)

flying for altitude is cool, but it is a multi edged sword. Yeah, it’s neat to see a rocket go out of sight, but it brings its own problems as well.

you need a field that will allow for recovery. NAR recommends MINIMUM 1000 foot wide field for a G motor, 1500 feet for 2 Gs. Preferably without Rocket Eating trees and rocket hiding bushes. That can be hard to find.

guidelines here at bottom of pager


you don’t want to be dropping your rocket into people’s backyards or roof tops.

most flyers like to fly a rocket more than once (or at least get it back and proudly display it!), recovery is challenging the higher the rocket flies (out of sight is not always a good thing.)

trackers are available but they do cost money, and they don’t always work (the sad refrain of the high powered rocketry enthusiasts, “I either lost or lawn darted my rocket and lost or destroyed all my electronics and motor casings!” Often the cost of those exceeds the cost of the rocket nose cone, body, fins, and motor reload)

point is, like Icarus, flying as high as you can isn’t always as optimal as it’s cracked up to be,
 

KilroySmith

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By the way, can you tell me what model rocket boosters are?
Most low-power rockets are pretty simple and don't have a booster - the rocket motor goes in one end of the rocket body tube, the nose cone goes in the other, like: https://estesrockets.com/product/001292-wizard/ . Some more complex rockets have two motors - a lower motor in a booster tube attached to the bottom of a simple rocket, like: https://estesrockets.com/product/002092-mongoose/ . The lower motor in the booster burns and launches the rocket to a couple hundred feet, and when it burns out it lights the upper motor and the booster falls off.
 

BABAR

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Then go design a rocket with multi cluster staging.
That was a fun one.
I did Three-Two-One. Three stages, three nose cones.

Bottom-booster (Stage 1) was three motor cluster, three tubes, two were C6-0 to a two cluster mid booster, third A8-3 with a nose cone for chute recovery

Mid-booster (Stage 2) was two motor cluster, two tubes one was C6-0 to a sustainer, other the A8-3 with nose cone for chute recovery.

upper stage just a single tube with an A8-3.
 

Ez2cDave

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If it's not too much of a bother, I like to get some advice on making a model rocket kit fly higher. Like a few general tips that can be used before/during launch. Or maybe some slight modifications that can be made to a model rocket.
( 1 ) Minimize drag ( eliminate Launch Lugs and smoothest finish possible ).

( 2 ) Optimize weight.

( 3 ) Use the largest, long-burn motor that will fit.

( 4 ) Fly out of a tower.

( 5 ) Use a Piston Launcher.

Dave F.
 

Vilius SR

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There’s no one thing that you can do to have your model rocket fly a lot higher- you need to make several incremental improvements that will make your rocket more and more efficient. This will allow it to reach the highest altitude that it can.

Here are some of the best improvements that you can make:

Stage your model rocket; Use 3 well-placed fins; Make symmetrical tear-shaped airfoils in your fins; Seal and sand smooth your fins; Reduce your rocket’s weight; Use a lower thrust engine to fly slower and higher; Make sure your rocket is stable;

Fill the groves in your body tube; Use an elongated elliptical-shaped nose cone; Sand and polish your entire rocket smooth; Use launch rail with fly-away rail guides or a tower or a piston launcher; Finally, launch on a hot and humid day.

source: https://simplerocketry.com/how-to-make-a-model-rocket-fly-higher-altitude-guide/
 
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