What's the deal with the E11J?

Quick question- I was looking at getting a 24mm RMS case and noticed the E11J motor. "Ooh," I thought, "What a great motor for light rockets when I want a bit of altitude!" Then I realized that it only has one delay: 3 seconds.

Why? What's the obstacle against making, say, and E11-6J?

That is already a full length delay grain in that case. They do make another full length delay in their slow delay formula for use with the F12-5, but they didn't certify the motor with it for some reason. Would it work? Maybe, maybe not.

This motor runs so soft. In most any application the E18-7 reload would be a better choice...

LithosphereRocketry said:

Quick question- I was looking at getting a 24mm RMS case and noticed the E11J motor. "Ooh," I thought, "What a great motor for light rockets when I want a bit of altitude!" Then I realized that it only has one delay: 3 seconds.

Why? What's the obstacle against making, say, and E11-6J?

Click to expand...

E11-3J is certified as a 4 second delay (see photos above). They are a fun low thrust motor with lots of black smoke. I fly them in a Fat Boy and Blue Bird Zero. I've seen an SLS Javelin fly on them.

I love E11's and F12's.

Ive got these as well. Great for the Big Daddy and they WILL lift the Cosmic Interceptor.

sl98 said:

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E11-3J is certified as a 4 second delay (see photos above). They are a fun low thrust motor with lots of black smoke. I fly them in a Fat Boy and Blue Bird Zero. I've seen an SLS Javelin fly on them.

Click to expand...

You show an E11-5J as well... Is that no longer certified or what? That's exactly what I was asking for...

Sent from my LGL44VL using Rocketry Forum mobile app

My understanding is the 5 sec delay is no longer certified....at a minimum it is not produced.

I have some of the 5sec delays and the "3" second delay. I've flown both and there doesn't seem to be much difference.

So, long story short:

AT originally made an E11-3J and an E11-5J. However the E11-3J came out to an E11-4 in cert testing and few people were using the E11-5, so they discontinued it.

Does that sound about right?

sl98 said:

View attachment 330903View attachment 330904

E11-3J is certified as a 4 second delay (see photos above). They are a fun low thrust motor with lots of black smoke. I fly them in a Fat Boy and Blue Bird Zero. I've seen an SLS Javelin fly on them.

Click to expand...

One more question: Is there any website that can tell me the certified delays rather than the manufacturer delays for a given motor? I couldn't find it on Thrustcurve. I'd like to make myself a list of actual delays for selecting motors.

LithosphereRocketry said:

One more question: Is there any website that can tell me the certified delays rather than the manufacturer delays for a given motor? I couldn't find it on Thrustcurve. I'd like to make myself a list of actual delays for selecting motors.

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Are you looking for something like this:
https://www.nar.org/SandT/pdf/Aerotech/E11.pdf

https://www.nar.org/standards-and-testing-committee/nar-certified-motors/

sl98 said:

View attachment 330903View attachment 330904

E11-3J is certified as a 4 second delay (see photos above). They are a fun low thrust motor with lots of black smoke. I fly them in a Fat Boy and Blue Bird Zero. I've seen an SLS Javelin fly on them.

Click to expand...

Just checked the NAR report and the E11-3 cert'ed at 2.8 seconds on its most recent time around. Different delay formula maybe?

LithosphereRocketry said:

Just checked the NAR report and the E11-3 cert'ed at 2.8 seconds on its most recent time around. Different delay formula maybe?

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Sounds like a good question to post in the AT GM thread.

If you look at the earlier certification document from NAR, only one delay was certified:
https://www.aerotech-rocketry.com/c...ts/NAR/reloadable/rms-24_40/e11j_nar_cert.pdf

Here’s a more recent certification document:
https://www.nar.org/SandT/pdf/Aerotech/E11.pdf

Steve Shannon

LithosphereRocketry said:

Quick question- I was looking at getting a 24mm RMS case and noticed the E11J motor. "Ooh," I thought, "What a great motor for light rockets when I want a bit of altitude!" Then I realized that it only has one delay: 3 seconds.

Why? What's the obstacle against making, say, and E11-6J?

Click to expand...

The HDK-12 is the Hobby Delay Kit for both the E11-3J and F12-3J. The HDK-13 is listed for the F12-5J only. But likely Aerotech dropped listing the E11-5J also for this delay kit. If you want a longer delay, try one of these.

Trident said:

The HDK-12 is the Hobby Delay Kit for both the E11-3J and F12-3J. The HDK-13 is listed for the F12-5J only. But likely Aerotech dropped listing the E11-5J also for this delay kit. If you want a longer delay, try one of these.

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But would that be within the limits of NAR certification? The E11J is only certified with HDK-12.

If not, how hard would it be for AT to get HDK-13 certified? Seems like it would have decent demand- the E11-3J is basically good for light draggy rockets as far as I can tell.

LithosphereRocketry said:

But would that be within the limits of NAR certification? The E11J is only certified with HDK-12.

If not, how hard would it be for AT to get HDK-13 certified? Seems like it would have decent demand- the E11-3J is basically good for light draggy rockets as far as I can tell.

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Using a different delay grain than as certified would be allowed at a Tripoli Research Launch as long as you’re a Tripoli member Level 2 or above.
For a manufacturer to certify alternate delays requires sending in a number of motors with the additional delay(s) just as if certifying a new motor. Delays cannot be certified except as part of a motor test.



Steve Shannon