Estes Big E and F Engines Getting Hard to Find.

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I have E16 boosters and I plan to try this. It makes sense.

Not sure how much Mammoth weighs but I built it per instructions.


Switch it up. I've heard an E16-0 to an F15 is a good boos combo.
The E16 has a slightly higher peak thrust, and it drops the booster weight quicker.

Also, how heavy is your mammoth, and where is it's CG? Mine weighs 12oz flat without motor and I'm about to put a half-moon balsa chute shelf in it to keep the bundle from sliding backwards.
 
Welp, my 'raincheck' for F15-6s is taking longer to come in than they predicted. Looks my Hobby lobby's warehouse may have been fit by the BP29 famine of '17 also.
 
I'll have to seeing by and give them a reminder....

Also this is rocket city, so those have a slightly higher turnover.
 
RickGr4, How did the launch go with the Mammoth and the PSII booster? I am curious as I am building the same rocket, but with strap on boosters in addition, so I am most curious about how the launch went.

Tinker
 
RickGr4, How did the launch go with the Mammoth and the PSII booster? I am curious as I am building the same rocket, but with strap on boosters in addition, so I am most curious about how the launch went.

Tinker

I will be launching Mammoth and Ascender with a booster next Saturday at the Tripoli MN launch. Depending upon how that goes I may launch Majestic, Trajector and Prowler with a booster as well.

I read one review where a Mammoth owner did not think the rocket responded well to a booster but I need to see that for myself.

I will report the results.
 
If there is a problem with stability when flying the Estes booster with a recommended Estes kit, PLEASE save the booster motor and take measurements of the nozzle.

I saw one go unstable several months ago and there was virtually zero wind. The rocket was very, very slow but it should have gone upward, but it did loops until it staged. I did an immediate visual inspection and saw that the nozzle was eroded larger and slightly out of round compared to other 29mm Estes motors (both fresh out of the pack and recently fired). I attributed the instability to the lower thrust and the deflected thrust. I've only seen a few flown and this was the only unstable one. It used stock 'Starter' and plug.
 
Will do,

I am always quick to get rid of used motors but I will do a better job of inspecting them post flight.[


QUOTE=shreadvector;1725570]If there is a problem with stability when flying the Estes booster with a recommended Estes kit, PLEASE save the booster motor and take measurements of the nozzle.

I saw one go unstable several months ago and there was virtually zero wind. The rocket was very, very slow but it should have gone upward, but it did loops until it staged. I did an immediate visual inspection and saw that the nozzle was eroded larger and slightly out of round compared to other 29mm Estes motors (both fresh out of the pack and recently fired). I attributed the instability to the lower thrust and the deflected thrust. I've only seen a few flown and this was the only unstable one. It used stock 'Starter' and plug.[/QUOTE]
 
My day at Tripoli-MN:

1. Launched SpaceX Falcon 9 with an E12. Great flight but a long walk to recover.

2. Launched Estes Majestic with an E16. Glorious flight but it took some searching to recover it from the soybean field.

3. Launched Estes Mammoth with a PS2 booster. Thought I put an F15-0 in the booster but it was actually an F15-8. Dumbest thing I have ever done. Mammoth rose off the launcher but nose dived into the ground. At first glace I thought it was history but I cut off the top 3rd of the body tube and reinstalled the shock cord mount. "Mini Mammoth" will live to fly again.

4. Launched Estes Ascender with a PS2 booster. Both stages had F15s installed. Wind was blowing at 12 to 15mph. Tripoli Launch Director advised that me I would lose the rocket but I launched it anyways. He was concerned about the wind and the rocket's center of gravity. 1st stage went well but second stage separation cocked the rocket nearly horizontal when the F-15 second stage kicked in. The rocket ended up in la-la land. The Gods of soybean fields have it now.

My conclusion? As others have said, Estes Pro Series rockets with Pro Series boosters only work in little to no wind situations.

The good news is the E12, E16 and F15 motors I used today were flawless. Shreadvector I saved the casings and glanced at them. I did not notice any issues but I will look more carefully at some point.
 
I've never seen the erosion on an F15 other than that one flight that went unstable.

In other words, there is no need to save and inspect used motors unless you had a strange flight.
 
My local rocketry dealer was telling me this week, Estes D motors are becoming hard to come by also - his explanation was that Estes' parent company Hobbico was in some financial strife and the motor shortages we are seeing is because of this..
 
My local Hobby Lobby is full of Estes D motors.

Also the last launch at Camden Ken Allen had D motors.


Sent from my iPhone using Rocketry Forum
 
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I've found a solution to the low thrust F15 issue at this local hobby store.
Cost an arm and a leg but It'll be worth it.

IMG_20170910_111240478.jpg

I have to distribute some lead baggies in the mammoth to make the 4 second delay safe though
 
6oz brings its coast down to 5secs lol.
Blue Thunder is the Vmax/Warp9 of mid power!

It'll be the maiden flight, so we'll see what happens
 
I had an idea to use an adapter and a E12-0 in the PSII Booster. The E12 has less total impulse, but more thrust at launch than the E16 and weighs a half ounce less. Does anyone think staging will be an issue?

The only problem is all the E12's at Apogee are from the latest batch reported to be CATO prone.....

Tinker
 
I'd vent the booster (drill some holes around the periphery fairly close to the top) to facilitate it not staging before the sustainer lit in that case. But it just might work.....
 
I realized that I don't have the time or a big enough field to serve as a test bed for Estes and the Pro Series rockets with boosters. Going forward I will be flying rockets such as Mammoth and Ascender single stage with Aerotech F engines.

I need to learn more about this and at some point I want to get to Level 1. However at this point I think that the Estes E2X Pro Series rockets may have CG issues when used with Pro Series boosters unless the wind is dead calm.
 
I realized that I don't have the time or a big enough field to serve as a test bed for Estes and the Pro Series rockets with boosters. Going forward I will be flying rockets such as Mammoth and Ascender single stage with Aerotech F engines.

I need to learn more about this and at some point I want to get to Level 1. However at this point I think that the Estes E2X Pro Series rockets may have CG issues when used with Pro Series boosters unless the wind is dead calm.
If you want to play here, you can pin / tape the booster and load a spent casing in the sustainer. The extra drag / weight can be useful for staying inside a constraint and / or practice A Thing in prep. for a larger field.

A Prowler, for instance, can be kept inside a park boundary​ by taping an E2X booster and flying from that.
 
I think I understand what you are saying but with a spent casing in the sustainer will that reliably eject the parachute?


If you want to play here, you can pin / tape the booster and load a spent casing in the sustainer. The extra drag / weight can be useful for staying inside a constraint and / or practice A Thing in prep. for a larger field.

A Prowler, for instance, can be kept inside a park boundary​ by taping an E2X booster and flying from that.
 
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