Good rocket suggestions for Estes E9 motors

Last year I bought a pack of Estes E9 motors to put in my two stage Fission rocket (the orange-and-black rocket in my avatar). I found out, much to my dismay, that this may not be a motor that is easy to find a good rocket for. It was my mistake creating a two-stage rocket that uses an E12-0 and then an E9-6. The motors plus the rocket were too heavy and after a LONG flight (2 seconds of booster, 3 seconds or second stage plus 6 seconds before deployment), the rocket was way over in a corn field where I couldn't find it (I WILL put a beeper in my next flights).

So, after that incident, I thought about the E9 some more and I think maybe it is a difficult motor to accomodate. It weights ~60grams, so to have a 10:1 thrust to weight ratio, you need 6 Newtons, or two thirds of its power, ONLY TO LIFT THE MOTOR. This means building an entire rocket around it that weights only 30 grams without the motor. Allowing a 5:1 ratio, which is too low where I fly because there is almost always 10-15km/h of wind (~3-4.5 m/s) and I do not have a 4 foot launch rod (I may get a rail later), means 120 grams for the rocket. Again, this is not very realistic, so maybe a maximum of 80 grams for the empty rocket.

Are there good kit choices for the Estes E9? Otherwise, making the lightest rocket with good fin area is the option, but it looks like it reduces the options for design.

What are your thoughts on the E9 and what to fly with it?

Estes Mega Mosquito, Estes STM-012, and Estes Bid Daddy are just a few.

Estes Magician flies very well on one.

+1 on the Magician

Maxi Alpha III likes E 9s too.

I've flown them in good wind on Estes MPRs many times. One of the last, my Tomahawk weathercocked way over and I got some ejection damage, but that was the only time, and it's always off a 3' rod due to it being 3/32". My overweight repaired Executioner (OOP) also angled way over, but even with maybe 1/3 altitude still landed downwind of the pad. These were similar to the Maxi Alpha 3 (same nosecone) but not quite as light. Also don't forget the later versions Big Daddy and Mean Machine can use them.

I have one rocket sort of made for them. 5 oz. w/o motor, 5.5" cone fin. Gets 400' and looks really cool on an E9, yet only would get about 550' on a F24 (which would send the Tomahawk over twice as high). You can actually see it slow down during the burn on a composite as the thrust drops off, where an E9 is steady until it cuts off abruptly.

Thank you for the suggestions. Quite a few to choose from.

Bill, could you do a short list of the Estes MPR you have flown with the E9s? The Executioner looks cool, but as you specified it is out of print.

Also, what is that 'one rocket sort of made for them'? Would you mind posting a picture?

I think I will end up creating something scratch that will be inspired by some of the suggestions. Probably a minimum diameter and semi-elongated rocket (not a squat one like the Big Daddy, for example).

Estes Baby Bertha. I put one (waaayyy...) up on a 29mm BP motor with a streamer and it did fine. Got it back, and was going to launch it on an AP motor, but ran out of daylight.

An E9 should be fine.

The Flis Kits Richter Recher was always a nice choice for the Estes E9 (3 per flight cluster)



Did I mention it is huge...?

That motor does have a long burn and relatively low thrust for its weight. So rockets prone to weather cocking can get started off at an angle and then have a lot of time to fly off under power in whatever direction they are headed. I've had more rocket crashes on E9's than any other motor. I prefer E12's over E9's in most cases, because the higher thrust provides more reliable flights.

However, when conditions are good, and there is no wind, and I have a nice 6' rod, the slower speed of the E9 is very cool. The Maxi Alpha Three flies great and straight on an E12, but under good conditions, it's a lot of fun to fly it on an E9 --- a great, slow, dramatic flight!

So I would say it's not just the rocket but also the conditions that make the E9 an appropriate choice. Fly your E rockets on E12's, and pull out the E9 on nice calm days.

On a side topic. The Executioner looks like a stretched Maxi Alpha Three (similar to a Colossus), but it has heavier plywood fins, not lightweight plastic. If you want to approximate an Executioner, you can use an extra length of BT80, a coupler and a bulkhead to make a payload section for a MAIII. It makes for a nice big rocket that is very lightweight. I have one of these that I can add or remove from my MAIII, which makes it really versatile. It's nice to have the option to fly it in long mode or short mode.

Vagabond also flies great on E9-6. I have one that I built completely stock and it goes just over 1000 ft on that motor with great eject timing.

The Estes Hi-Flyer XL will go up nearly 1000 feet on an E9. The D-Region Tomahawk is a nice one, if you can still find one; however, don't use model glue on it. Use CA.

Also, the Super Neon XL.

ThirstyBarbarian said:

That motor does have a long burn and relatively low thrust for its weight. So rockets prone to weather cocking can get started off at an angle and then have a lot of time to fly off under power in whatever direction they are headed. I've had more rocket crashes on E9's than any other motor. I prefer E12's over E9's in most cases, because the higher thrust provides more reliable flights.

However, when conditions are good, and there is no wind, and I have a nice 6' rod, the slower speed of the E9 is very cool. The Maxi Alpha Three flies great and straight on an E12, but under good conditions, it's a lot of fun to fly it on an E9 --- a great, slow, dramatic flight!

So I would say it's not just the rocket but also the conditions that make the E9 an appropriate choice. Fly your E rockets on E12's, and pull out the E9 on nice calm days.

On a side topic. The Executioner looks like a stretched Maxi Alpha Three (similar to a Colossus), but it has heavier plywood fins, not lightweight plastic. If you want to approximate an Executioner, you can use an extra length of BT80, a coupler and a bulkhead to make a payload section for a MAIII. It makes for a nice big rocket that is very lightweight. I have one of these that I can add or remove from my MAIII, which makes it really versatile. It's nice to have the option to fly it in long mode or short mode.

Click to expand...

Thanks for the insights. I am now building for E12s and E15s and I'll design something for E30 later.

I will keep the E9s for my specially designed rocket and calm wind days, as you suggest.

Some time down the line, maybe later this year, I'll be able to use a launch rail, which will really help with the lower thrust motors.

Hnefi said:

Vagabond also flies great on E9-6. I have one that I built completely stock and it goes just over 1000 ft on that motor with great eject timing.

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The scratch build I worked on today looks similar to the Vagabond, only with bigger fins. In fact I will use 4 fins of the Red Max shape.

morlock said:

Thanks for the insights. I am now building for E12s and E15s and I'll design something for E30 later.

I will keep the E9s for my specially designed rocket and calm wind days, as you suggest.

Some time down the line, maybe later this year, I'll be able to use a launch rail, which will really help with the lower thrust motors.

Click to expand...

Another great E motor is the single-use Aerotech E20. That was the first composite motor I ever tried, and it was great!

One day I flew my MAIII in its longer configuration with the payload section on E12-6, E9-4, and E20-7, one right after the other. It was a lot of fun to compare all the flights. I used an altimeter and got data on all 3 motors in that one rocket. One interesting thing was that the E12 and E9 both sent the rocket to almost exactly the same height, but the speed and acceleration were very different.

Here's the thread about that day of flying.

https://www.rocketryforum.com/showt...ing!-Lots-of-rocketry-quot-Firsts-quot-for-me!

morlock said:

It weights ~60grams, so to have a 10:1 thrust to weight ratio, you need 6 Newtons, or two thirds of its power, ONLY TO LIFT THE MOTOR.

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This is unduly pessimistic because the initial thrust spike of the E9 is almost 20 newtons, it's only the average that's 9.

mikec said:

This is unduly pessimistic because the initial thrust spike of the E9 is almost 20 newtons, it's only the average that's 9.

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I understand why you would say this, but I don't believe my affirmation is pessimistic at all. If you look at the graph below from my simulation in Open Rocket, I would even say it is pretty realistic.



The rocket leaves the rod as the thrust reaches 18 N. Since the progression in thrust is pretty linear, the average thrust FROM IGNITION TO LEAVING THE ROD is in fact very close to 9 N.

I'd be glad to see data that shows otherwise. In fact, if the rod was longer, the average would be higher. Same thing if the rocket was heavier and thus took more time to leave the rod, but then the thrust to weight ratio would be reduced.

I still believe the E9 is a motor with a very low thrust for its weight.

mikec said:

This is unduly pessimistic because the initial thrust spike of the E9 is almost 20 newtons, it's only the average that's 9.

Click to expand...

I understand why you would say this, but I don't believe my affirmation is pessimistic at all. If you look at the graph from my simulation in Open Rocket, you will see that my affirmation is rather very realistic.

View attachment 256112

The initial thrust spike reaches 19 N, for a very brief moment, but the rocket leaves the rod before that, just as the thrust reaches 18 N. Since the progression in thrust is pretty linear, the average thrust before leaving the rod is in fact very close to 9 N.

If the rod was longer, the average would be higher. Same thing if the rocket was heavier and thus took more time to leave the rod, but then the thrust to weight ratio would be further reduced. If the rocket was lighter, it would leave the rod earlier and the average thrust would be lower. Since the weight of the motor would be very significant (because it is heavy), the average thrust to weight ratio may not even be increased.

I still believe the E9 is a tricky motor to use with a very low thrust for its weight. It requires a light rocket, long rod, and low winds.

10:1 TTW is only a guideline. You're right that it takes a while for the thrust to ramp up, and it also depends on how stable the rocket is, how long the rod is, wind speed, rocket weight, etc. All that said I've had successful flights on the E9 even with the heavy D-Region Tomahawk, though it takes some care and attention to conditions. Now that Estes has the E12 it's probably a better choice for most uses, with only a bit less total impulse than the E9.

As stated earlier: Big Daddy

Estes QCC Explorer is a great flier, and one of my favorite looking rockets these days.

-Hans

If you have OpenRocket this is a proven design:

View attachment MRE04124.ork

morlock said:

Thank you for the suggestions. Quite a few to choose from.

Bill, could you do a short list of the Estes MPR you have flown with the E9s? The Executioner looks cool, but as you specified it is out of print.

Also, what is that 'one rocket sort of made for them'? Would you mind posting a picture?

Click to expand...

I've only flown the Exec and Tomahawk.



I was talking about the one on the right. It's not an ideal rocket but the smoke kind of billows around the cone fin and it makes more smoke than most rockets its size. Its performance is especially bad on every other motor but the E9... sort of slow but steady flights. It also does 29 mm , unfortunately the F15 ejection charges try to rip it apart. According to sims, getting it to 999 feet on a G80 would require adding one pound of ballast, otherwise it is less.

My Super Neon XL flies pretty good on a E9, as does my Mega Mosquito.

+1 on the Vagabond although I only put an E in it when it's calm so I don't have to walk too far (it's fine off the rod even when it's a little windy).

For the Super Neon and the Tomahawk I've had issues with both on an E9 when it's windy - I save them for calmer days.

I built a 29mm Baby Bertha, and it flew well stock (just swapped out engine mount) with yellow glue, and recovering on a streamer. I just made a sim for the same Baby Bertha using an E9-6. With 0.75 oz nose weight, it has ~1.3 cal stability and should hit about 1411 feet. If the nose weight is dropped to 0.50 oz, the stability sims to 1.1 cal and an additional 17 feet to 1428 are gained. Both eject right at the apogee. With the 29mm BB, I used a 12 foot crepe paper streamer, doubled. Recovery was about 100 feet away from pad.

View attachment 24mm Baby Bertha.ork

I think I've still got a G55 around here somewhere...

My Estes Eliminator turned in a lovely flight to 1299 feet on an E9-6 today.... Sadly this model which can trace its lineage all the way back to the Enerjet 1340 is OOP. Some are still around on clearance.

DRAGON64 said:

The Flis Kits Richter Recher was always a nice choice for the Estes E9 (3 per flight cluster)

Did I mention it is huge...?

Click to expand...

Or even 3xE12-0 + 3xE9-6! :wink:

One more to add...the Vagabond is a perfect rocket for this motor.

Cheers,
Michael

Vagabond flies great!

Nate

i put an E9 engine in a hybrid rocket built with parts from the hyperbat and honest john.

used honest john tube, plus hyperbat nose section... and incorporated fins from both..... the thing went surprisingly straight... no wind though. ended up recovering it after it basically went out of sight on way up...

was awesome

here's a video:

https://www.youtube.com/watch?v=DLKwTOSDNjc&feature=youtu.be

I think the Vagabond looks like a great rocket. And now I'm sort of regretting selling my D Region Tomahawk kit. I got rid of that one, and I didn't buy the Vagabond when I saw it on clearance at my Hobby Lobby, because I was getting into high power and didn't expect to fly much 24mm anymore. Now I'm facing a bit of a clampdown on my rocketry budget for the foreseeable future, so I might not be buying as many HPR motors after my current stash runs out. I think E motors are a great price point in rocketry, with a lot of value for the cost. They give a very satisfying launch, and you can fly some decent-sized rockets. Also, you can stand much closer to the pad than you can with HPR, and I like to be right there when it goes off!

D and E motors are my favorites for park flying. I don't like rockets going too high in the park, so I tend to favor draggier ones. If you want to fly a low-thrust, long burning E9 motor but keep altitude down, high-drag is better than high weight for keeping low and slow. The light rocket can accelerate quickly at the beginning and get off the pad fast, but then drag takes over and keeps it from going too fast and high for the rest of the flight. I'm thinking something like a Mega Mosquito would be perfect for low-and-slow flights on low-thrust, long-burn E9's.

I won a Red Flare at a launch and haven't built that one yet. I think that would be good on an E9. The MAIII is heavy enough that it wants an E12, except on very calm days. But the E9 would probably work well in the lighter Red Flare.

I also bet the Estes V2 would be good.

Has anyone tried using an adapter for an E12 or E9 in any of the 29mm E2X kits? They are probably too heavy for the E9, but I would think an E12 would work fine.