Model Rocket Engine Code Explained for Beginners
Вставка
- Опубліковано 20 тра 2019
- www.ApogeeRockets.com -
A common question in model rocketry is what does the engine code printed on the side of the motor casing mean? An even more important question is how do you use that engine code to pick the right motors for your model rocket?
This is a very basic introductory video for those people that are new to rocketry. In it, I'll go through the letter and the numbers and explain what each one means, and how you can make a comparison in order to select the right motors for your next flight.
If you prefer this information in written form, you can view our website and select any rocket engine. We put this information on all the engine pages so that people selecting motors for the first time have some background information to review. - Наука та технологія
Man, I thought I knew the numbers enough to teach people. I was wrong. Thanks for the tutorial.
you're welcome.
yea same
Great rules of thumb! I didn’t think about the weathercocking with a lower average thrust number. Those thrust curve illustrations in rocket tutorials do help visualize the relationship between the total power of the rocket motor (the letter) and the average thrust (the first number). So a B4-4 versus a B6-4 means both motors have a total power of “B”, in newton/seconds. That is total power, how many newtons on average applied for how many seconds. Both motors have the same total power. But a B6 will apply more newtons for fewer seconds. It burns out faster than a B4 but has more initial “oomph” than a B4. As Tim says in the video, a motor with a high average thrust is sometimes needed for a heavy rocket as a heavy rocket is harder to get going. You want to make sure your heavy rocket has enough speed when it leaves the launch rod so that the fins have enough air moving past them to stabilize the rocket in flight. A picture is worth a thousand words. Those model rocket thrust curves you see in model rocket catalogs show visually how a motor with a higher average thrust number delivers more average thrust than a motor with a lower average thrust number, BUT that thrust ends sooner than the motor with lower average thrust. Because the motor with the lower average thrust puts out that thrust for LONGER, it has the same OVERALL power as the motor with the higher average thrust.
That helps. Now I know why the bigger rocket on went 12 feet into the air. 😂
You guys seem sus
What does that even mean brother man
@@dillonbledsoe7680 I have no idea. Lol. That was a while ago. I must have been drunk or something.
@@bakermob29 🤣
Great information on rocket terminology and the uses for different sizes and delays. Came looking for a small amount of info on engine sizes, but found all of the info I did not know I needed to know!
Same!
Launched my first A engine rockets today with my two girls, ages 4 and 6. It was fun, now we want more power! Thank you for the explanation and interesting video.
dont stop until you start using AI thrust vector. muahahahaha
One thing I really miss in the low power engines, are the Series II engines with a centerbore. I used to have a two stage Centuri rocket named Long Tom, and I'd fly it with a C6-0 first stage, and a B14-5 second stage. The rocket was just short of three feet tall, and even with the C6 first stage engine the liftoff would be relatively slow. When that second stage ignited though, the rocket would seemingly disappear.
Awesome video. Thank you so much. Explained very well and you took your time to explain too. Great!
Nice video! I’m doing the rocketry challenge in school, and I found this very useful!
Good explainer. Thanks Tim.
Great review! Straight to point and HD video quality! Thank you for the information!
Glad you like it. Thank you.
I can't express how much this helped
Great instructional video. Was using A8-3's for an old Estes 18mm motor powered Honest John, for small launch areas. Since I'm on a budget, A10-3 with 13mm/18mm adapter works even better and I get 4 launches instead 3. ❤
Excellent video. Now that I know, I can explain it to my kids. Thank you.
Thank you, this is actually something I wanted to know about.
Amazing video, Tim really knows his craft
Thanks Brian. Just trying to help people out.
Thank you so much sir. I run and aerospace club and really needed a motors guide.
This guy just explained all the pertinent information that I should have known about in 1982, while I was destroying random homebrew rockets and the property of my neighbors. Including my english teacher's patio door.
Thank you! That explanation was worthy of Dr. Werner Von Braun himself!👌
Thank you. I've never been included in such high company. I feel honored by your thoughts.
Very interesting thanks for posting this me and my son have been having a lot of fun with a small model rocket we are going to start making our own
lol…had the old Bandit rocket that didn’t need wadding as it used baffles to cool the gas before it hit the chute. Had reglued fins in so many time it got heavy. Used too long a delay and it went up over grandmas house and straight into the ground. Uncle said I don’t think anybody survived that one. 😂
Many thank my son is getting his first setup for Christmas and we already fly fixed wings drones and helis. Looks like it’s just as much info to divulged in rockets as well
Great explanation! Awesome video!
This is a very good video. Thank you! 👊🏻
Very informative, well done!
Thanks for answering my question at the 9:35 mark. My question was whether or not a -0 motor has an ejection charge or not. Great instructional video!
Great point!
No,a booster,or zero delay,has NO ejection charge. Only propellant. When it burns out,it ruptures forward,shooting hot gas and bits of burning propellant forward into the nozzle of the second stage engine,which ignites the propellant.
i like the new intro....
Nice overview.
IIRC from way back when I was active in model rocketry, the XX-0 engines have no delay AND no ejection charge. They are for booster stages only and can set your terminal stage on fire if used there.
For normal there stay XX-P. P for pluged no extraction charge
I was slightly confused because I saw a lot of people saying C5 is more powerful than C6 thanks for this better explanation
It is deceptive, and I understand the confusion. You have to go a little bit deeper, and look at the thrust-vs-time graph and compare the C5 versus the C6. The C5 does indeed have a more powerful kick, and the initial momentary thrust spike is therefore higher than the C6. But then the C5 thrust drops down to a lower level for most of the duration of the burn time. And it actually burns for a longer period of time than the C6, which is why its "AVERAGE" thrust is lower than the C6. That is why it is a 5-Newton average thrust, which makes it seem less powerful than the C6.
Unless you're flying competition models where you really need to tune the right motor to the rocket model for optimum performance, you probably shouldn't be too concerned about it. If your rocket would be OK on a C6-3, it will also be OK on a C5-3. The C5 would be "slightly" better for heavier rockets, or ones that have more drag (like really big fins).
To see a chart comparing the thrust curves, go to: www.apogeerockets.com/Rocket-Motors/Estes-Motors/18mm-Motors/Estes-Motors-C5-3
Very helpful. Thanks
Excellent info 👌 very useful indeed 😊
Thanks, helped a lot 👍
Will you be doing a video like this on HPR motors?
The basic principles are the same: a G motor is twice the impulse of an E, etc etc.
I'M USING AN N CLASS MOTOR FOR MY MOST RECENT PROJECT WISH ME LUCK
Has that monstrosity taken off yet?
Luck
😀
How did it go
@@shadowdeslaar Guess he blew himself up 🤷🏾♂️
I always wondered why sometimes out of 2 rocket motors the same size, one was way more powerful than the other. I guess ones just not filled up all the way.
There is something else going on. The rocket motors are tested for consistency by the National Association of Rocketry. So It is unlikely that one motor is way more powerful than the other (all else being the same). You'd have to be a bit more specific on what your question might be.
Thanks for the info
Thanks for the info!
Would you also choose a higher number if you wanted to launch a heavier rocket? Or does that not make a difference with such small engines? I've found that on windy days, a longer delay is better so the parachute deploys closer to the ground and has less of a chance of drifting into trees or anywhere far from the launch site.
You were paying attention! Yes. On a heavier rocket, you want to use a higher number after the letter.
But on windy days, I typically use a shorter delay because the rocket is going to weathercock into the wind a bit. So it won't fly as high, and hence, it will get to that peak altitude in a shorter amount of time.
Using a longer delay on a windy day will allow the rocket to arc over and be closer to the ground (as you mentioned), but now you have to worry about the opening speed of the parachute. If the rocket is screaming towards the ground and the parachute suddenly opens, there is a higher chance of ripping the canopy. Then the rocket will fall the rest of the way to the ground at a higher speed and you're likely to bust a fin. So it is a balancing act on selecting the right delay.
what if I use a high thrust engine in the first stage and a low thrust one in stage 2 or 3 will that go pretty well?
That will be pretty good idea. You want high thrust at liftoff to get air flowing over the fins to make sure the rocket goes straight up. Once it is moving, then a low thrust motor is great to just keep it on the stable trajectory. Go for it!
Bought one of these in a yard sale and fucking got addicted lol. I’ve gone to the moon and back about 7 times now lol
Sometimes I feel like a dealer... But this is a good addiction to have.
Super great video thank you
Super, thank you!
nice teaching..
At least on Estes engines, there is also the color coding. Red first-stage booster. There was also the use of the Green, Blue, Purple and Black to differentiate the engine use as well. Been too long to remember all those details. Guess I could check the webs. :-)
One comment I'd make is regarding the first stage booster (zero second) engines. Unless they've changed in the long while since I flew rockets with Estes engines, the boosters do not have an ejection charge like any of the other engines with a delay (3 to 10 seconds for example) before the ejection charge fires.
Estes booster engines (red zero seconds) do not have a cap at the top of the propellant stack. That cap is present to contain the loose propellant pebbles used for the ejection charge. The boosters - without that cap and no ejection charge pebbles at the top of the propellant stack - will begin a process of 'propellant burn-through' as the last of the booster propellant burns from the nozzle end to the top end of the engine. That thin amount of the last bit of propellant breaks down from the pressure inside the rocket motor and is forced up the engine tube into the nozzle of the 2nd stage engine. These bits ignite and as they are forced into the next nozzle, they ignite the propellant in the next stage's engine. The force of the next engine's ignition causes the separation from the booster engine of the first stage.
We generally used scotch tape between boosters and the next engine on top. As the engine above the booster ignited, the tape melted to allow a clean separation. For a 3-stage rocked, booster 1 to booster 2 with scotch tape and booster 2 to 3rd stage engine with scotch tape. This meant multi-stage rockets didn't/couldn't use the metal engine hooks that you see on single stage rockets. The booster and upper-stage engines needed to be friction fit using masking tape, etc.
Prior to Estes making their non-booster engines a bit more tamper proof with the gray molded propellant caps, there was just a round paper cap pressed into the top end of the engines. With a pair of tweasers you could pull that paper cap out and dump out the ejection charge pebbles. There were 'mostly nefarious' reasons to collect them. Thus the current molded caps. At one time (maybe still) Estes sold a dummy display engine that was cut in half length-wise to show the layers. Yes, we made our own. Hey, kids think they're indestructible and can get away with that stuff. We did all survive those years.
Great info in your videos. Subscribed!
Green = Single stage Red = Booster (first stage) Purple = Upper stage Then there are blue labels for plugged situations
hey, would anyone know a good kit for a c6-5 model rocket, thanks.
i remember we weren't allowed to launch any rockets greater than C unless we were deemed skilled enough to properly build rockets by the teacher. in that case, we could use D engine rockets when launching at the dog track. never got to go to any of the locations where something bigger could be used
4:06 They'll go approximately the same height but at a different rate of ACCELERATION. They have different ( as represented mathematically on a graph ) ACCELERATION RATES. The higher the number - the FASTER the rocket motor will take it's rocket to a specified height.
Whats inside these ?
Hello. Thanks you for useful video. In the Estes engine, the injection explosion occurs in the reverse direction. I would like to install an injection unit separately, so how do I handle the injection pressure?
What do you mean by handling the ejection pressure?
After a few seconds of burning, does not create pressure in the direction of the parachute? Isn't the parachute ejected with that pressure? How can engine fire a parachute?
@@Parklab2space Go to our website and watch the video on how engines work: www.apogeerockets.com/Tech/How_Rocket_Engines_Work
Thanks. I quickly understood. But If I want to use a separate injection device like CO2 EJECTION DEVICE, is there a way to not use ejection charge pressure? How to deal with ejection charge pressure?
@@Parklab2space You have to "plug" the rocket motor. See our UA-cam video on how to do that.
Great stuff
For a moment I thought I hit on a NASA how to. Better. Very nice presentation. A+ if NASA reads this or Elon why not pass out free rocket launch to Mara and Beyond and bring on Real Buzz A!
So from a A10 en a B10 comed both a trhrust of 10 Newtons? So i guess the A and B are there to indicate the time? I ask the question because i want to calculate what my mininum trust is needed for a 800 gram rocket? Any calculation or videos to calculate this? Or is this just trail and errror? Greets from belgium
We recommend the RockSim software for determining the flight parameters of your rocket.
Oh scheesh I forgot those engine codes; my parts box w/ various eng categories carried to the park to launch a few rockets - the faithful eng igniters stuffed into the nozzle with a bit of wadding.
Hello Tim. I bought rocket stability floppy discs from you 20 years ago. Can I trade them in for a CD/DVD of the same thing? Probably not but just wanted to say hello.
Sorry. I don't have a clue what was on them from 20 years ago. So can't duplicate anything.
Why/how does Estes determine engine size recommendations on the package? What is the danger in exceeding the listed motors?
The way we go about determining engine recommendations is to use the software called RockSim. You can quickly get a very good idea how high and fast the rocket will go. Here is a video on picking rocket motors: ua-cam.com/video/iwrjTgStOLM/v-deo.htmlsi=STsKxbwlADFb1qVp. The only danger of exceeding the listed motors is determining whether or not the rocket can withstand the forces of flight. Estes only picks "their own" rocket engines. But you can often substitute motors from other manufacturers that they don't list. The RockSim software will give you the list of motors that will work (if you build the rocket strong).
I need that engines but not avialable to get give me idea please
Is the letter power or work?
Which motors goes up to 1.5km please tell me
I am waiting for you
Are there also motors for fast acceleration so of can leave the tube then fire up the big motor
For high acceleration, you want a motor with a big number right after the letter. To see how fast they will accelerate, this is where you need to use software to predict the performance, because it will depend on the size of the rocket, it's weight, and the launch conditions.
Still debating...Any suggestions? Needing one with enough power to lift about 100 grams of the good stuff 😉
You kno wassup🤣💪🏼
what about wind speed velocity??
I don't understand your question. Sorry.
Fantastic video, but a bit of misinformation towards the end. Motors that end in “-0” do not have an ejection charge at all. They are only loaded with propellant and are used as boosters. They should NEVER be used in single stage rockets as the recovery system will not be deployed and your rocket will come down ballistic.
With Estes black powder motors, the engine codes are also color coded. Most of the motors shown in the video had a green code. Green means it’s a general purpose single stage or upper stage motor. The A8-0 and C6-0 shown in this video had red codes. The red means it is a booster motor. The C6-7 also shown in the video had purple text. Purple means it’s primarily an upper stage motor, but could also be used in lightweight rockets.
I also want to touch on the letter “T” that is at the end of some motor codes. On motors such as A10-3T shown in the video, the “T” at the end signifies that this motor is mini-size.
I disagree with you that they don't have an ejection charge. They do. There is a flaming fireball that ejects forward when the propellant breaks through the last sliver of black powder. In fact, without that from occurring, the Apogee Flying Machine kit-- would not work to eject the streamers from the strap-on booster pods. I stand by what I say in the video. They do have an ejection charge that can be used to eject recovery devices.
@@apogeerockets The reason a fireball shoots upward is the high pressure inside the motor (between the burning propellant and the nozzle) breaks through the last little sliver of propellant remaining into the relatively low pressure above the motor. Since booster motors do not have a clay retaining cap, the propellant must serve as its own retaining cap. As the propellant burns, it gets thinner and thinner (looking at a cross section of the motor). Eventually, the propellant will get so thin it simply cannot hold back the internal pressure anymore, and the high pressure breaks through, sending a fireball upward.
@@solarflea4115 I totally understand the physics. You can watch all the cool animations on our website. I still call it an ejection charge, because is CAN be used to eject a recovery device.
Had the triple stage delta dart. Sunny day and launched great but lost sight of it and never found it. Found the first stage only
What if you don't want to have the motor eject the parachute? Do you just put it in an enclosed motor casing?
Yes. It is called a plugged motor.
Please do A video on how two stage model rockets work I cant find anything.
You'll find the video on our website at: www.apogeerockets.com/Tech/How_2-Stage_Rockets_Work
@@apogeerockets luv you guys
When it’s windy, we always went with a longer delay, reason? Because with a longer delay the rocket could fall into our area and be a little closer to us. In other words we did a little test one time. Two identical rockets, windy day, both could hit about 1500 feet. The shorter delay one stayed higher and landed about a quarter mile from us. The longer delay would drop farther in elevation before chute coming out, and landed about 4 or 500 feet away is all. The longer delay probably dropped 2-300 feet before opening, hence closer landing to us. But like I said this was windy conditions.
I miss flying model rockets
Great video, thanks. I believe the correct terminology is Newton and not Newtons.
Wait how does the parachute ejection work? You have parachute connected to top of the engine?
see the video at: www.apogeerockets.com/Tech/How_Rocket_Engines_Work
@@apogeerockets Interesting. Thank you very much.
i want to know about how max thrust estes rockets produce
There is a website called thrustcurve.org. They have far more information on each rocket motor you may want.
I make my own F motors and fill it all the way up because I don’t use ejection charges.
Finally, mystery solved.
Used a C6-7 in amazon rocket with a little wind..... Bad idea. Wish I had seen this video sooner... Still had a "Blast" ;)
Are there motors without delay, so that I can use my own electronic recovery system?
Yes. But they are high power motors. The usually end in a "P" for plugged.
Thought the 0 was no ejection charge because it burns to the next motor in a two or three stage system?
@@MrCyphrex I think it just ejects immediately cause 0 second delay
which model rocket motor has the longest burn time i wish they made one that has a 300 second burn time
We sell a rocket called the F10. It has an 8-second burn time. You'll find it on our website.
joe selzer mate that’s 5 minutes
@@davidroberts1852 yes tight
The lower the number after the first letter, the longer the burn time. The longer the burn time, the lower the average thrust, so the rocket must be very light and aerodynamic, or for a second stage where the sustainer is moving already.
What do you do if you live outside of the US? And how do know the speed of the motor?
That is a very good question. Unfortunately, I don't have an answer for you. Maybe some other viewer will comment on this topic with good answers.
If you can't get a motor shipped to you, Charlie Garcia made a video on how to make your own solid rocket motor
Newton to pound calculator
Any low power motor with a dash zero, such as the A8-0 mentioned, has no ejection charge. They merely burn through. These motors are first stage motors meant to fire a second stage. He makes it sound like they have an ejection charge which will push out a parachute. I hope this isn’t what he means.
It will eject a parachute. And it will ignite a upper stage motor. I call it an ejection charge, and I stand by that 100%. You can call it what you want if you so desire.
I need help so my model rocket says it can hold a A8-3 up to a c6-7 but only the a A motor fits in it what should I do
What specific A motor fits into it? See the video above.
Was looking for a q motor...
Thanks lot
I wished i can make a space shuttle model out of those
Only thing i don’t understand how the parachute deploys itself , the chute never comes out when I’ve done it
lol rocketry for beginners and they explain in Newtons. Why not explain it in weight? (C6- engine = 10 Newtons = 1 kilogram or 2.2 pounds)
What I did learn in this video is that all C- motors have the same amount of propellent. Just the higher the number, the faster it burns. ^^probably answered my own question there.
and I launched Estes rockets first in like 1983.
Your explination of the parachute delay is also great.
I can't find any place to buy model rocket engines... I live in Spain, can someone help me find any place or web where I can buy them from Spain?
@Adrià Lázaro Me da que nos quedaremos con las ganas jajaja Yo ya ando pensando en fabricarlo yo mismo
@Adrià Lázaro Yo ahora no puedo hacerlo, pero en verano lo intentaré, si logro algo ya te diré como hice o si fracaso xD
Can you ignite them with Visco fuse ?
I would imagine you could. When I was a kid we always used firecracker fuses.
D12-7 24mm Motor for 500g - 700g is it ok to fly up to 300 meters?
Sorry. I can't pull a number out of the air for you. You'll have to run your computer simulations, because there is more to it than just the weight. The launch conditions matter as well. The software we use is called "RockSim."
@@apogeerockets Ok sir but I need a cheap motor rocket around 8 - 15 dollars and a long burning time. is that ok?
@@izumisama_ UA-cam is not where you buy rocket motors. You go to our website. You can pick and chose from the motors listed there. We have hundreds of rocket motors of all varieties.
Do you have an actual store?
www.apogeerockets.com
Fun fact, I use to glue fins and a nose cone directly to engines, PS C6-5 in a rocket is really the best.
Quite the engineer.
10:20 So what does the "T" at the end of the numbers mean??
This was asked before. But no one really knows why Estes added the T decades ago. We can surmise that it means "tiny." But that is just speculation. It really only indicates that it is a 13mm diameter motor. Which is tiny in comparison to their regular size 18mm motors.
Q::: what is the minimum launch TWR demand of a model rocket 🚀 that could go vertically up, at least 500 meters??? Thanks
You'll need to run the simulations, because you didn't specify the weather conditions. The software that I recommend is RockSim. You'll find it on our website (see description above). There is a free 30-day version you can use to test your rockets.
@apogeerockets there's got to be a minimum, though
I meant, a known minimum
@@kareemsalessi If you have a formula, send it to me. But I can tell you that there isn't a formula, because it it dependent on a LOT of variables. Running a simulation will give you all the information you need. Why not just do it?
@apogeerockets OK, THANKS. On the Estes rocket specs, I had previously found TWR==6 as the minimum safe ratio, although, I like to hear of practitioners of their personal TWR experiences.
Can you confirm the letter is the burn time, and the number is just take off velocity?
No. Please watch the video again.
@apogeerockets I asked before I finished watching ! Haha I'm sorry. But thank you for responding!
My first rocket was a c6-5 with a noscone and some fins slapped on
Hii sir I live in india can I shop from apogee
We do not ship rocket motors outside the USA. But everything else we can ship to India.
An A8-0 designation means it is booster motor and has no ejection charge.
What do you call that heat and chunks of propellant that fly forward, and can be used to push out a recovery device, like in the "The Flying Machine" model rocket kit that we sell at ApogeeRockets.com? I beg to differ with people that a -0 on the end of the code is not an ejection charge. If you don't want the ejection charge, you should used a -P motor, which means plugged. Because you will get an ejection charge is you have a -0 motor. Absolutely-guaranteed.
@@apogeerockets See last paragraph in NAR Standard Motor Codes
www.nar.org/standards-and-testing-committee/standard-motor-codes/
@@apogeerockets I understood them to be the ignition method of the upper stage. The upper stage motor would cause the ejection of the lower stage.
@@psgouros I'm not sure what your question is. But maybe this will help with separating the bottom stage: ua-cam.com/video/H89Msbs7-JA/v-deo.html
What doe the P mean in D9-P?
Plugged - No ejection charge.
1/8A is basically just a bottle rocket, right?
At last which is a powerful beast motor
where to get that engines .
They used to be sold at hobby shops. This information was pretty in Estes catalogs or on the back of the packages.
thanks sir but how to use these?
We did a video on that at: ua-cam.com/video/-6WnAY9Qego/v-deo.html
But wouldn't the weathercocking be helpful for recovery on windy days.
Should you be launching on windy days? That is the question you have to think about.
@@apogeerockets Well, relatively. I was thinking in terms of your recommendations for "windy" v.s. "calm" days.
My thinking was that the weather vaning into the wind would make for a lower apogee farther upwind so that wind drift after chute deployment would end up closer to the launch point.
And how do you start the engines?
see our video at: ua-cam.com/video/-6WnAY9Qego/v-deo.html
@@apogeerockets thank you very much bro