How much BP in Estes ejection charges?

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Goblin

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Does anyone know how many grams of black powder is used for ejection charges in Estes 13mm, 18mm & 24mm motors?
 

RocketMonkey

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I'm sure estes does...not sure they will tell you.
 
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Micromeister

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Thats nearly impossible at least with estes motors as the propellant, smoke delay, ejection charge, nozzle and clay cap are all rammed into a single plug (grain).

I have photos but I'm not sure they'ed be allowed.
 
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Mark_1984

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Just wondering why you would want to know ?

As an aside, a few years ago I had a couple of 1/2A motors where the top clay cap was too thick, or maybe there wasn't enough BP, and the ejection charge vented though the bottom of the motor causing a deployment failure, closely followed by a lawn dart.
Cheers
Mark
 
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Bazookadale

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As an aside, a few years ago I had a couple of 1/2A motors where the top clay cap was too thick, or maybe there wasn't enough BP, and the ejection charge vented though the bottom of the motor causing a deployment failure, closely followed by a lawn dart.
Mark
Bring back the days of the paper cap!
 

Pantherjon

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Bring back the days of the paper cap!
Then you would have loose BP particles in the package of motors:(..I have some older AT single use 29mm motors where the paper caps adhesive has degenerated and there are BP particles in the package..Will have to remove the cap and refill the ejection charge bay if I intend to use those motors..

The clay cap is the best solution, but quality control can be improved to insure that the cap isn't too thick..
 

powderburner

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I don't know it you know this, Goblin, but over the years Estes has varied the amount of ejection charge material that they use. Early on (1960s, 70s, and I think into the 80s) they used less (and they only held it in there with a stamped paper cap). When, over the years, model rocket designs evolved into bigger and bigger critters, it became necessary to increase the ejection charge to maintain reliable deployment. (Compare the volume that needs to be pressurized at ejection between the old Estes Goblin and the newer Estes Mean Machine.) Plus, you always get minor variations in manufacturing throughout any batch of motors, and also between batches. So, the amount of ejection charge varies.

Very approximately (and I do mean VERY), the ejection charge in an Estes 18mm motor is around 1/2 or 3/4 gram of material. For 24mm motors it's more like one full gram, maybe more. I don't remember the amount of ejection charge normally loaded into 13mm motors but you can bet it's less than 1/2 gram.

I am not sure why you are asking. Just as a cautionary note, be advised that there are few uses for Estes ejection charge black powder once it is removed from a motor (yeah, there are NAR rules about that too). This particular BP is in a form (compacted chunks) that does not readily lend itself to other applications. You would have to do some processing, and since most folks do not have the proper industrial equipment (or safety equipment), that could be pretty dangerous to your eyeballs and fingers.
 

jadebox

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..I have some older AT single use 29mm motors where the paper caps adhesive has degenerated and there are BP particles in the package..Will have to remove the cap and refill the ejection charge bay if I intend to use those motors..
I built a saucer to fly to use the motors I have that are missing the ejection charges.

-- Roger
 

init 6

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Thats nearly impossible at least with estes motors as the propellant, smoke delay, ejection charge, nozzle and clay cap are all rammed into a single plug (grain).
Nah, they're colour coded look at this:




:)
 

MarkII

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...

I am not sure why you are asking. ...
I'm not sure either, but I can imagine that it might be informative to know approximately how much "pop" they are packing these days. There has been a lot of talk in the past couple of years about the engines that Estes makes now having "shotgun" ejection charges. I know that there are BP calculators on the web that help HPR fliers figure out how much black powder to put into their ejection canisters for DD. If we knew how much BP Estes puts under the clay cap, then perhaps someone could use such a tool to figure out how much pressure it really does generate in a given airframe.

I don't know, but that is what immediately come to my mind when I first saw the thread a couple of days ago. Let me stress right here that this is not an issue for me personally, but I can see it being a matter of concern for someone who has had a few models get blown apart by the ejection charges in Estes engines. I did kind of expect to see something in this thread by now that gave a rationale for the question.

Mark \\.
 

MysticalRockets

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Discussing altering engines in any way violates the rules.

This thread should be immediately removed by the moderators, and is being reported.
 

Handeman

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In that case, let me get in here while they're still taking names! :D

I can't tell you exactly how much powder is in the Estes motors. I do remember the amount in each type of motor being posted in TRFI.

I have not had problems with "shotgun" ejection from any motors. In fact the only problems I've had is weak ejection. There seems to be a lot of reasons for this. One is nozzle erosion. I had one motor that ejected the nose cone, but not the chute after the C motor flew to an altitude I usually get on an A. When I got it back, the nozzle was over a 1/4" in diameter.
 

Goblin

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The reason I asked this question is because I’m pretty sure that there was a post in the old forums that contained this info. I simply never wrote it down, and thought somebody here might remember.

Some rocketeers out there make their own motors. I’m one of them. Sure, I use store-bought motors at launch events, but I’m working on homemade Estes equivalent motors for my own personal use, when I launch by myself. I have no interest in “altering” or dissecting a commercial motor to find this info out, and don’t recommend anyone else doing so either. I’ll just have to take the “trial and error” route to dial in the ejection charge amounts.
 

RoyAtl

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I have not had problems with "shotgun" ejection from any motors. In fact the only problems I've had is weak ejection. There seems to be a lot of reasons for this. One is nozzle erosion. I had one motor that ejected the nose cone, but not the chute after the C motor flew to an altitude I usually get on an A. When I got it back, the nozzle was over a 1/4" in diameter.
If you had THAT much erosion on a manufactured model rocket motor, it was either defective or damaged.
 

Len B

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Discussing altering engines in any way violates the rules.

This thread should be immediately removed by the moderators, and is being reported.
Certainly, altering motors is a violation of the safety code. Gluing down the ejection charge to make a C6-plugged is a slippery slope. That is a tough one. How about a known failure? Let's say a C6-5 in a long rocket like a clone of an Andromeda. There are many cases where the ejection charge has not been enough to pop the cone off. Is it a violation to put a little more BP on top of the clay (or paper in the case of an old historic motor that we are legally using in the NAR motor testing case)? Is that a problem? I have a clone kit and I surely have heard that the standard charge has not been enough to pop the cone. Should I hold my breath and pray that maybe it happens? I think people get a little hot to trot over reporting and such. Is this one of those cases?

LenB
 
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Handeman

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Certainly, altering motors is a violation of the safety code. Gluing down the ejection charge to make a C6-plugged is a slippery slope. That is a tough one. How about a known failure? Let's say a C6-5 in a long rocket like a clone of an Andromeda. There are many cases where the ejection charge has not been enough to pop the cone off. Is it a violation to put a little more BP on top of the clay (or paper in the case of an old historic motor that we are legally using in the NAR motor testing case)? Is that a problem? I have a clone kit and I surely have heard that the standard charge has not been enough to pop the cone. Should I hold my breath and pray that maybe it happens? Or, should I "Heaven forbid!!" alter the motor by taping in another little bit of BP to get it off? Sometimes, I think people get a little hot to trot over reporting and such. Is this one of those cases?

LenB
Personally, I don't see adding a little of your own BP in a rocket is altering the motor. You're just adding some additional BP and locating it where there will be the least delay between the motors normal ejection and the burning of your extra BP.
 

atticus

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"Just wondering why you would want to know ?"

When I first saw Goblin's original post, I thought perhaps he wanted to know if it was enough to toss the laundry on a extra long or fat parachute compartment.
I then waited for Shreadvector to ask what Estes said when he (Goblin) contacted them.
Like others, I remember seeing this infomation on TRF or ROL but couldn't come up with it easily.
In any case, on Monday morning, when nobody had responded, I e-mailed the query to Estes. I gave them directions to the thread so they could answer and gain some goodwill or send it to me and I would pass it on.
I received an immediate acknowledgement of my inquiry.
So far nothing.

This is what bothers me now.
In the current economic unpleasantness, you would think a company would have plenty of underused personel to bend over backwards to respond to any question from members of their market base, no matter how trivial.
I know the principals of several other vendors respond to questions concerning their products on this and other forums in a timely manner.
I can imagine a 'meeting' of execs to discuss the situation and if and why they should respond, along with what the impact of such action, if any, would have on the bottom line. Then decide to check with their lawyer and take lunch.

Tongue firmly in cheek and not holding my breath, Tim
 

MarkII

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It might be proprietary information that they don't want to reveal.

Another person to ask about this would be The Rocket Doctor ("Ask The Doctor") over at YORF.

Mark \\.
 
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Carl

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It might be proprietary information that they don't want to reveal.
They already revealed it in a patent application, so it is not proprietary any more. The current amount of .5 grams in 18mm engines has been fairly constant over the years. It is the same we used in the 60's. Remember, all black powder is not the same.
 

Peartree

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Personally, I don't see adding a little of your own BP in a rocket is altering the motor. You're just adding some additional BP and locating it where there will be the least delay between the motors normal ejection and the burning of your extra BP.
If I recall, there was a discussion of this on TRF 1.0 and the result was that this was sometimes done during NAR contests and was not considered to be altering a certified motor and therefore acceptable under contest rules. Not everyone agreed that this was safe and appropriate for rocket contests.

One of the avid contest folk could say for sure whether I am recalling this correctly.
 

shreadvector

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If I recall, there was a discussion of this on TRF 1.0 and the result was that this was sometimes done during NAR contests and was not considered to be altering a certified motor and therefore acceptable under contest rules. Not everyone agreed that this was safe and appropriate for rocket contests.

One of the avid contest folk could say for sure whether I am recalling this correctly.

As has been explained to TARC participants, the Federal regulations for use of Black powder are reasonably clear. You can use it in antique firearms, but use in other applications requires an LEUP and at that point you no longer have a "Model Rocket", you have a "High Power Rocket" - even if the power level of the motor is fairly low. Just like having a C motor with over 80 newtons of average thrust would make it a High Power Motor. But the use of black powder is different than the average thrust example. I'm sure I'm not explaining this clearly, so I'm sorry in advance.
https://frwebgate1.access.gpo.gov/c...SdocID=188341392994+8+2+0&WAISaction=retrieve
Read the part about how the exemption ONLY applies to use in antique firearms.
https://en.wikipedia.org/wiki/Antique_guns#United_States
 
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