Saturn V

I got an Estes Saturn V. Have not flown it yet. Now most say on the D motor it gets only about 100-150' and is under powered to the point that flight time is min to deploy.So my "Q" is, any reason why I cannt just stick an E motor in it?So the thing hangs out the MMT a little.The end of the D is at the max distance UP inside the BT anyways.So I would think having the E hang out some wont hurt a thing.

The problem with your idea is that the E9 has a lower initial thrust than the D12. You would be better off using a composite E, either in RMS or SU form.

G.D.

I wouldn't recommend using an Estes e motor in it's saturn V. I tried that with one 2 years ago and it didn't work out well...in fact it was a disaster.

Man, I can kit build-em ,design-scratch-build-em, But Ill be the first to tell ya, this motor thing I am just not getting at this point.And thats not a good thing at all for a rocketeer. I need to get a DVD or some kind of schooling on this issue.:gavel::gavel::gavel::gavel::gavel::gavel:

An E15-4 single use was the perfect replacement for the D12. There's a few 24/40 RMS reloads that would work fine as well.

DO NOT EVER use the LOW-THRUST wimpo Estes E9 in any Saturn V or any other 4" diameter rocket.
You will instantly re-kit the rocket with a power-prang that will need trash bag and broom recovery.
If you want to use an E in the Saturn V, use a 24mm Aerotech E15, E20, or E30 in single use, or reloadable 24mm RMS E18 or E28.

The Estes E9 motor really should be used in rockets no more than 2.6" in diameter that weigh less than 8oz. It really does NOT have enough average thrust for anything more. The DUMBEST thing I have ever seen reccomended by a manufacturer was when Estes added the E9 to the motor list for the re-issue Maxi-Brute V2. All that resulted in was more kit sales due to crashed underpowered V2's.

Scotty Dog said:

Man, I can kit build-em ,design-scratch-build-em, But Ill be the first to tell ya, this motor thing I am just not getting at this point.And thats not a good thing at all for a rocketeer. I need to get a DVD or some kind of schooling on this issue.:gavel::gavel::gavel::gavel::gavel::gavel:

Click to expand...

You don't need to get a DVD.

You can go online and order this book:



It will explain it in simple enough terms.

The E9 v D12 comparison is a bit deceptive, since the the E9 is huge by comparison.

The impulse class relates to the amount of energy they carry, with the upper limit "E" range being double the upper limit of the "D" range. The number that follows is the average rate that energy is released. See the attached chart. You will note that the D12 is really a D10.7 and the E9 is really a E9.2, derived from the published data.

Also note the higher impulse spike of the D12 to give the rocket a bigger "kick" off the pad. That, along with the D12 being a motor that is only 59% of the weight of a E9, make it a much better motor in many applications.

Greg

Scotty Dog said:

Man, I can kit build-em ,design-scratch-build-em, But Ill be the first to tell ya, this motor thing I am just not getting at this point.And thats not a good thing at all for a rocketeer. I need to get a DVD or some kind of schooling on this issue.:gavel::gavel::gavel::gavel::gavel::gavel:

Click to expand...

I fly on E9's all the time.. Call me the "King of E's" hehe.

Anyway, you have to design VERY carefully to use the Estes E9. In the proper models, the E9's give nice slow long burn flights due to the low thrust ratio...but they are NOT the kind of things you want to go slapping into kits not designed for them...even ones that supposedly are can be dicey...as others have noted.

If you have anything coming in over 8oz you have to be *really, really* careful on an E9.

You're better off using composite single use or reloadable motors. Aerotech E15's make an excellent choice for kits that need more oomph.

-C

cgould said:

Anyway, you have to design VERY carefully to use the Estes E9. In the proper models, the E9's give nice slow long burn flights due to the low thrust ratio...but they are NOT the kind of things you want to go slapping into kits not designed for them...even ones that supposedly are can be dicey...as others have noted...
-C

Click to expand...

I have one rocket that has the E9 as a recommended engine, the Estes EggsCaliber. I'm guessing I may want to be extra careful using an E9 with an egg on board. D12 is also on the list...maybe I'll just stick with those.

GregGleason said:

You don't need to get a DVD.

You can go online and order this book:

It will explain it in simple enough terms.

The E9 v D12 comparison is a bit deceptive, since the the E9 is huge by comparison.

The impulse class relates to the amount of energy they carry, with the upper limit "E" range being double the upper limit of the "D" range. The number that follows is the average rate that energy is released. See the attached chart. You will note that the D12 is really a D10.7 and the E9 is really a E9.2, derived from the published data.

Also note the higher impulse spike of the D12 to give the rocket a bigger "kick" off the pad. That, along with the D12 being a motor that is only 59% of the weight of a E9, make it a much better motor in many applications.

Greg

Click to expand...

Thanks for the info.I guess whats got me baffeled is I look at the motors by "Power Range" not the take off thrust and average and that.Like you said-in comparison by looks and the fact that the "power" doubles from a-b-c-d-e- gets me messed up. Ya know-"Engine room, we need more POWER!!!!!" anywhoo ,looks like Ill be ordering me a book,cuz I really do want to GET this!!!!!!!!!!

Scotty Dog said:

Man, I can kit build-em ,design-scratch-build-em, But Ill be the first to tell ya, this motor thing I am just not getting at this point.And thats not a good thing at all for a rocketeer. I need to get a DVD or some kind of schooling on this issue.

Click to expand...

All this was found on line, here and there. I tried to put some info together so you can start to get a handle on the motor thing.


Newton, The amount of force required to accelerate one kg, one meter per second per second. 4.45 newtons equals one pound of force.
(EMRR Glossary Library)

Newton-Second, The typical unit of measurement for rocket thrust. One newtonsecond is one newton of thrust maintained for one second.
(EMRR Glossary Library)

Impulse, Thrust force multiplied by time. The units of measurement are usually Newtons and Seconds.
(EMRR Glossary Library)

Total Impulse, The total thrust produced by a rocket motor across its full burn time. Usually expressed in Newton-seconds.
(EMRR Glossary Library)

Average Thrust , The total impulse (in Newton-seconds) divided by the length of burn time. Example; a K185 motor has a total impulse of approximately 1400 Newtonseconds, and burns for 7.5 seconds. 1387.5 Newton-seconds divided by 7.5 equals 185 newtons average thrust.
(EMRR Glossary Library)




Motor Designations

Each AeroTech composite hobby rocket motor or reload kit has a designation
which provides important information about performance. The designation is read as follows:

G64-4W

First Letter
The first letter is a code which indicates total impulse in Newton seconds produced by the motor. Each succeeding letter has up to twice the power of the preceding letter. A ‘G’ motor has up to 160 N-seconds of total impulse.
(Aerotech 2009 - 2010 Catalog, page 3.)

Total Impulse: The total thrust produced by a rocket motor across its full burn time. Usually expressed in Newton-seconds.
(EMRR Glossary Library)




First Number
The first number indicates the motor's average thrust in Newtons. A Newton is equivalent to 0.225 pounds of force.
(Aerotech 2009 - 2010 Catalog, page 3.)

Average Thrust: The total impulse (in Newton-seconds) divided by the length of burn time. Example; a K185 motor has a total impulse of approximately 1400 Newtonseconds, and burns for 7.5 seconds. 1387.5 Newton-seconds divided by 7.5 equals 185 newtons average thrust.
(EMRR Glossary Library)




Second Number
The second number shows the time delay, in seconds between propellant
burn-out and activation of the ejection charge.
(Aerotech 2009 - 2010 Catalog, page 3.)


Second Letter
The second letter indicates the propellant formulation of the motor.In this case the "W" indicates "White Lightning". Additional letters or numbers may
be added to denote other performance characteristics.
(Aerotech 2009 - 2010 Catalog, page 3.)


Then you need to find out about the 5:1 launch ratio.
__________________

Does any of that help?

bradycros said:

Does any of that help?

Click to expand...

Not being a smart *** just need to mull it over.I guess its like, I need to do some equations or proplems like in the back of a book. EX-If I had a motor that was such and such "what would the total impulse be? Ill get it. I just havent had much time dealing with motors. At this time Im a LPR BAR. I do thank you for your time and others for the help. Whats this? Did I here SNOW in New England !!!Get the rocket sled out boys:roll: Ya-"It is snowing up here."

Scotty Dog said:

Not being a smart *** just need to mull it over.I guess its like, I need to do some equations or proplems like in the back of a book. EX-If I had a motor that was such and such "what would the total impulse be? Ill get it. I just havent had much time dealing with motors. At this time Im a LPR BAR. I do thank you for your time and others for the help. Whats this? Did I here SNOW in New England !!!Get the rocket sled out boys:roll: Ya-"It is snowing up here."

Click to expand...

In time the pieces of the motor thing will fall into place.

Scotty Dog said:

Thanks for the info. I guess whats got me baffeled is I look at the motors by "Power Range", not the take off thrust and average and that. Like you said-in comparison by looks and the fact that the "power" doubles from a-b-c-d-e- gets me messed up. Ya know-"Engine room, we need more POWER!" anyways, looks like Ill be ordering me a book, 'cuz I really want to GET this!

Click to expand...

Look at this chart. Ask questions you might have. Like, 'why are there two bars for the E class motor'?

bradycros said:

Look at this chart. Ask questions you might have.

Click to expand...

That still doesn't fully explain it though - just based on that chart, I would assume that any E could outlift any D motor, and that's simply not true. You also have to account for average thrust.

Very roughly, the letter tells you how high the rocket will go, the number tells you how fast it will get there. So, an F240 and an F10 will get your rocket to (very roughly) the same altitude, but the F240 will do it much, much faster.

This doesn't account for the need for safe speed off the pad though. An F10 is a very fun motor, but in a heavy rocket, an E30 is a better choice. The E30 has the higher number, so it will leave the pad faster, even though it won't go as high (assuming the F10 even stays straight coming off the pad).

So, for heavy rockets, look at the average thrust, not the total impulse.

Don't feel badly; I didn't get it at first, either.

As you already understand, each "bigger letter" of motor is more powerful than the letter below it -- "powerful", in this case, is defined as the total thrust delivered by the motor over the course of the burn.

The trick there is that the letters don't cover a single total thrust number, but a range. For example, the "impulse limit" of an A motor is 2.5 newton-seconds, and the "impulse limit" of a B motor is 5.0 newton-seconds. So, it's tempting to think of a B as "twice as powerful" as an A, but that's not necessarily the case. A B motor can deliver anywhere from 2.51 newton-seconds (i.e., just a smidge more powerful than an A) to 5.0 newton-seconds (i.e., just a smidge less powerful than a C). For example, looking at the engine data over on the NAR site, the Estes B4 motors produce 5.0 newton-seconds, while the Quest B4s produce only 3.84 newton-seconds.

So, the "increase the letter by one, double the power" is a rule-of-thumb that may not be entirely accurate.

The first "number" in the motor designation describes the motor's average thrust over its burn time (though, as has been pointed out, that isn't always 100% accurate, either). A B6 and a C6 will both (in theory) be delivering an average thrust of 6 newtons...but, it's likely that the C will have a longer burn in which to deliver that average, since it will have a higher total impluse than the B.

The issue with the Estes E9, as has been noted, is that, for its high total impulse, its average thrust isn't that high, which makes it unsuitable for heavier rockets (which will need a comparatively high initial thrust to get them off the pad safely). (Also, note that the NAR page shows that Estes E9s produce a total thrust at the low end of the E range.)

Edit: cjl said it more clearly than I could!

cjl said:

That still doesn't fully explain it though - just based on that chart, I would assume that any E could outlift any D motor, and that's simply not true. You also have to account for average thrust.

Very roughly, the letter tells you how high the rocket will go, the number tells you how fast it will get there. So, an F240 and an F10 will get your rocket to (very roughly) the same altitude, but the F240 will do it much, much faster.

This doesn't account for the need for safe speed off the pad though. An F10 is a very fun motor, but in a heavy rocket, an E30 is a better choice. The E30 has the higher number, so it will leave the pad faster, even though it won't go as high (assuming the F10 even stays straight coming off the pad).

So, for heavy rockets, look at the average thrust, not the total impulse.

Click to expand...

The man is trying to get a handle on the basics, why don't you help him with that instead of saying you don't like the way I am trying to do it? How much information do you think he can absorb at once? If you want to try and present the basic facts in a better way, please feel free to do it. All the finer points you've made are wasted if he dosen't get what's going on in that basic chart.

bradycros said:

The man is trying to get a handle on the basics, why don't you help him with that instead of saying you don't like the way I am trying to do it? How much information do you think he can absorb at once? If you want to try and present the basic facts in a better way, please feel free to do it.

Click to expand...

That's exactly what I did.

Your chart doesn't actually explain anything about the problem he is trying to get a grasp of (specifically, why does an E9 lift less than a D12). Your chart does a good job showing that each letter is a range, but not about the lifting power. Your chart shows clearly that an E might only be 3% more powerful than a D, but it still shows it as more powerful (and therefore, from that information alone, you would assume that it could lift more). Thus, if a D motor can lift a rocket, then by your chart, I would assume that any e motor, regardless of which one I chose, must have more powerful and could therefore safely lift the rocket.

I was trying to include the relevant matter here, which is actually the average thrust. That is the reason why an E9 lifts less than a D12, why a G25 lifts less than an F240, and why a K135 lifts less than an H999.

cjl,

What you keep refering to as 'my chart', came from apogeerockets.com. If you have issues with it, address them with 'ol Timmy VM. The chart does what it was intened to do, show the basic differences the motors have and how the total impulse could fall anywhere within their own A, B, C, D, or E range.

Impulse; Thrust force multiplied by time. The units of measurement are usually Newtons and Seconds.

"Impulse" had to do with how much energy the motor puts out over the course of its entire burn. Think of it as kind of like horsepower. It is a measure of the motor's total work capacity.

"Thrust" is basically the amount of force that the motor is applying at any given moment. It is a measure of how much power or muscle the motor has. Think of it as the amount of torque the transmission can apply to the wheels.

Some motors are like marathon runners - they aren't especially fast, but man, they can keep going forever. Others are like sprinters - amazingly fast out of the blocks and down the track, but they peter out after just a short period of time. They can't sustain that power for very long or for very far.

Here's another analogy: Imagine that you have been sent to the home improvement store to buy a cinder block. You don't have a car, so you have to bring the block home from the store, which is a half a mile away and you only have a limited amount of time to do it in. By the time you get through the check-out line at the store, you have 20 minutes left to get it back home. You can bring it back by walking slowly while you drag the block behind you on a rope. You won't move very fast and your arms won't pull very hard, but by the time you are done, you will know that you have expended a pretty good amount of energy.

You could also do it by repeatedly picking up the block and heaving it as far as you can down the road until you get it home. You will exert a lot of power each time you hoist it up and toss it, but you won't be able to keep that up for very long. It's a pretty good bet that your muscles will give out long before you get it home. You'll still have a bit of a way to go when the 20 minute deadline catches up with you.

If you used the first method, you expended a lot of energy but not necessarily a lot of force. If you used the second method, you exerted a lot of force each time you picked up and tossed the block, but you quickly ran out of it long before you got the block home.

In the first example, the amount of force you exerted was low but long in duration, so you ended up putting out a lot of energy. You had low thrust but a large total impulse. In the second example, you exerted a lot of force but could only keep it up for a short amount of time and you couldn't complete the task. You had high thrust but a lower overall total impulse.

Another good illustration of this difference, using rocket motors this time, is to compare an Estes C11 with a Quest D5. The C11 has an average thrust of 10.86 Newtons, which is nearly triple that of the D5's average thrust of 3.82 Newtons. So why is the Quest motor in a higher impulse category than the Estes motor? Look at the burn duration. The C11 burns for a total of 0.81 seconds. The D5 burns for 4.61 seconds. The C11 exerts a lot more thrust, but because of its short burn time, it only puts out a total of 8.8 Newton-seconds of energy. The D5 exerts much lower thrust but burns for quite a bit longer, and it ends up putting out a total of 17.61 Newton-seconds of energy. The Estes motor's total energy output (its total impulse) puts it in the C range of motors. The Quest motor's much higher total energy output, or total impulse, puts it in the D range.

An Estes E9 is in the E range of impulse, because that is how much total energy it puts out. It burns for over 3 seconds, which is a pretty decent amount of time for a black powder motor. But the E9 only exerts a peak force (thrust) of 19.47 Newtons and has an average thrust of 9 Newtons. Although it is an E, it doesn't have much as much muscle as other E motors, so it can't heave as heavy of a rocket. A big part of the reason for this is because the E9 is the only certified E motor that uses black powder propellant; all of the other E motors use composite propellant. APCP is a much more potent propellant than black powder.

i agree that motor classification is very tricky, i just kept researching and asking people and sooner or later it kinda just clicked.

If you want to use an E9, and your rocket can accomodate estes D12's, then i'd say the aerotech E15 will work amazing. It is the same physical size as the D12, and it burns for only 0.5 seconds shorter than the estes E9, but it's total impulse is close to the maximum for the E range.


This has nothing to do with what i was saying before, but it is kinda what everyone else is saying. an estes B6-4 and an estes C6-4 have the same average thrust, but because a B has a maximum of 5 newton seconds, and a C has a maximum of 10 newton seconds, the C will fire for about twice as long as the B.

It is tricky and with saying that, I dont want yous guys getting in to a battle over my lack of knowlege. I accept ALL that is posted and get a little bit of info out of each one.Then Ill put my ducks in order and it will "Click". One thing I know I was looking at wrong Is the need to look at each motor in thier own "range". And you can- Kick it in the butt and get-er going or just push-er along.Its funny cuz I read about the Q D-5 and didnt get why some had lost there rockets using it. I was like ITS a "5" :confused2: Now I see cuz it just keeps pushing and pushing. I think I got that rite :gavel::gavel: Anywhoo- Thanks

Scotty Dog said:

Ill put my ducks in order and it will "Click". One thing I know I was looking at wrong Is the need to look at each motor in thier own "range". And you can- Kick it in the butt and get-er going or just push-er along.Its funny cuz I read about the Q D-5 and didnt get why some had lost there rockets using it. I was like ITS a "5". Now I see cuz it just keeps pushing and pushing. I think I got that rite, Anywhoo- Thanks

Click to expand...

Here's a link to the page the infamous chart came from. www.apogeerockets.com/Aerotech_Reload_Motors.asp#24_Reloads
Scroll down several pages until you find the chart. There's an explanation that goes with the chart.
Let us know if that gets you pointed in the right direction.

cgould said:

If you have anything coming in over 8oz you have to be *really, really* careful on an E9.

-C

Click to expand...

That parallels my own experience with the E9 as I have flown the heck out of these in large but light gliders. One of my nicer flyers on this motor is my BT80 gliding Bomarc that weighs 9z sans motor. I wouldnt go any higher than this though.

I do beleave I got it.And speaking of the Saturn V, its not the best flyer anywhoo. I been on youtube and watched a bunch of launches of the V. Not to many went up real straight.So,back to motors.My anology goes like this. Lets say I have bottles of water under pressure. Now an A has 1/2 oz of water, and it can be released slowly or all at once.B=1 oz (2x)of water that can be released slowly or all at once. If the pressure (power)(water)in the bottle is released slowly there is not must thrust But it will continue to release till pressure is gone at that rate.If the pressure is released all at once there is more thrust at that time but the pressure runs out quicker.So if I have a bottle with 5psi in it and let it out all at once it will have more thrust (take off) than a bottle with 10psi but is only aloud to release 3psi at take off, but will continue to release the 3psi till pressure is gone =longer burn time but less thrust at take off. So the A is less powerful (5psi vs 10psi)tech speaking than the B , but the A has more thrust at take off. Hope you get my drift But I do think I got it.

AstronMike said:

That parallels my own experience with the E9 as I have flown the heck out of these in large but light gliders. One of my nicer flyers on this motor is my BT80 gliding Bomarc that weighs 9z sans motor. I wouldnt go any higher than this though.

Click to expand...

My rocketcam project, discussed in this thread https://www.rocketryforum.com/showthread.php?t=15605 flew on an E9 motor, and checked in at 7.5 oz.

You can see in the video as seen from the rocket that the thing sat on the pad for a brief moment after ignition, THEN it started moving up the launch rod!

You have to make sure that whatever heavy rocket you fly on the E9 is capable of being stable at speeds barely fast enough for most fin designs to work! You can bet this will be the case using the typical length of launch rods.... :y:

Now, having said that, if you design the rocket right, nothing is more impressive than the slow majestic flight of a rocket on an E9!

Just have to be REALLY careful with those motors!

---One observation I've come to notice...if the rocket "catches" or "binds" on the rod even a little bit, you rob a lot of what little "oomph" the motor has to give while on the launch pad...to minimize this, my launch lugs are stood off from the rocket body slightly to keep the rod from rubbing on the airframe on the way up. That really seemed to make a big difference, and allow me to successfully fly rockets that come in on the heavy side for an E9.

-C

cgould said:

---One observation I've come to notice...if the rocket "catches" or "binds" on the rod even a little bit, you rob a lot of what little "oomph" the motor has to give while on the launch pad...to minimize this, my launch lugs are stood off from the rocket body slightly to keep the rod from rubbing on the airframe on the way up. That really seemed to make a big difference, and allow me to successfully fly rockets that come in on the heavy side for an E9.

-C

Click to expand...

What I tend to do with such max size/wt gliders for a given motor is to use oversized 1/4" lugs and fly off 6' rods. I even have a very large C6 powered glider that gets this exact same treatment as well as others.

The original Estes Saturn V was designed to fly on a cluster of 3 C-6-3s, making it a D-18 equivalent. One was actually launched inside the Astrodome!:eyepop:

Has anyone here ever CHAD launched it with Estes D's ?