Estes E9. Why?
 

Does anybody know why Estes made an E9 instead of an E11 or E12? With an already functioning D11 and D12, it seems that keeping the same nozzle as one of the D's would have made basically a longer burning D. The reduced thrust of the E causes some problems in certain heavier models. Then we might also have an E booster as well.

Any thoughts?

In the mid-1990s, Estes did have a 24mm E15 (Actually, it was an E11-E12).

The first batch of these motors worked well but, after that, the failure rate climbed to a much higher percentage. I remember watching a LOC Viper III launch with three of these Estes E15s and have two of them cato.

Hobby shops were instructed to 'destroy' (Water soak) all inventory of this last run of Estes E15s (I worked in a hobby shop at the time and the warehouse called me to ask how to water soak the motors. I tried to just have them give me the moters but they told me 'no').

The Estes E9 motor runs at a lower casing pressure which requires it to contain more black powder to bring the performance up.

Bob

I got it. If they wanted to make a higher impulse BP motor, they would probably have to make a thicker walled motor casing. The lower impulse of the E9 is necessary to work with the 24mm motor casings they use now.

don't forget that Quest will be bringing its BP DEF engines to market in Spring of 2009. Hopefully the Global Economic Meltdown will not delay these engines getting to the marketplace as scheduled. The EF is 28mm not 24m, but there is to be an E12 and F12, and the E is near 100% E, so just hold on a little bit longer.

terry dean

I can't wait for these new engines. Add that to the reintroduction of the Estes A8-0, and this should be a fun year to fly rockets!

As I recall, the original Estes E motors had a burnthrough problem, I saw one CATO and we later realized the casing had failed.

Here is the info regarding the upcoming Quest motors: D8, E12 & F12:

http://www.rocketryplanet.com/content/view/2522/28/

I love the E9, but you have to cluster them in anything medium size or bigger.
I had an Estes Maxi Honest John that got destroyed by an E15 cato. I still have the parts, and will one day rebuild....

Since he supposedly has already had them in hand (or in shipping container) since before NARAM, I would suspect he wants to get them on the market as soon as he can get through the bureaucracy.

Stuart,

I have a couple of the re-issued Estes Kits and parts from my own prang at the Bonneville salt flats in Utah back when I workeed for Matt Steele at North Coast. Durn that salt is hard...BTW, it was an experimental NCR E20 that did the HJ in. Up was spectacular...down was gravity.

Anywho, I can help you out if I have an idea what you need.

Chas

Oh! Clustered E9's are a LOT of fun :) I love them in the Richter Recker. The long burn is really nice. I have flown the E15 before and actually prefer the E9. Only real problem is that, with the low overall thrust they couldn't do an effective booster...