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What do you call a motor with no ejection charge

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rocketsonly

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Hey, what is the term for a motor with no ejection charge?
Thanks,
Matthew
 

powderburner

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If it is a motor that came from the factory with no ejection charge, and no delay charge, then I call it a booster motor.

If it is a motor that has had the ejection charge removed, then I call it an illegal motor, and an almost certain problem that I wish you would save for another launch day when I am not attending.
 

rstaff3

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I sometimes call them lawn darts (that is a motor that was supposed to have a charge, but didn't :))
 

Micromeister

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Matthew:
Estes BP motors with the motor delay designation -0 are listed as Booster motors. used for the first stage in multi staged models and/or sometimes in clusters. -P indicate Plugged motors used in the estes race cars.

Or if you removed the ejection and delay train from a motor it's exactly what Powderburner said...Illegal!
 

vjp

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Hey, what is the term for a motor with no ejection charge?

If it was supposed to have an ejection charge, but didn't, I call that - well, I call it something I can't say here.
 

hokkyokusei

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Originally posted by Ryan S.
generally called a 'plugged' motor
No, a plugged motor is just one sort of motor without an ejection charge. For example a booster motor has no ejection charge, but it is not plugged.
 

BlueNinja

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Do you mean a motor that doesn't have a charge from the start, or if the charge fails to go off? If it doesn't pop, I call it a failure. If it has none from the start I call it a plugged or booster motor.
 

Ryan S.

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Originally posted by hokkyokusei
No, a plugged motor is just one sort of motor without an ejection charge. For example a booster motor has no ejection charge, but it is not plugged.
Hey, what is the term for a motor with no ejection charge?
exactly my point. He asked what is the term for amotor with no ejection charge and I said a plugged motor
 

cls

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if it doesn't pop I call it a *&#$&@ or a &!@)!- or sometimes a #&@#&@. :)
 

hokkyokusei

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Originally posted by Ryan S.
exactly my point. He asked what is the term for amotor with no ejection charge and I said a plugged motor
Your statement appears to imply that all motors without an ejection charge are plugged motors. This is not true, as a booster motor has no ejection charge, but it is not plugged.
 

cls

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booster motors have no delay, but they do have an ejection charge.
 

Ryan S.

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you beat me too it, often the booster will seperate because of the pressure build up. It isnt a designated ejection charge but it sure acts like one sometimes
 

Missileman

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It is kind of a matter of semantics.
In discussing black powder motors the propellant is black powder then a slower burning delay charge followed by an ejection charge of black powder. Now we look at a booster motor, take away the delay charge. when the propellant burns through it builds pressure in the airframe, enough to eject the motor, or even a nosecone. I am currently using a booster motor to move a piston to activate a switch for upper stage ignition.
IMO booster motors do indeed have an ejection charge.
Plugged motors D11p and E9p have no ejection charge at all.
They serve their own purpose. I have a Hobby Labs SR71 that requires a plugged motor.
 

hokkyokusei

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Booster motors do not have an ejection charge. Some forward pressure is created as they burn through, but this is not an ejection charge.
 

powderburner

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Originally posted by missileman
IMO booster motors do indeed have an ejection charge.
I get the impression that some of you guys have never read the insides of an Estes catalog. Then again, those catalogs are pretty much unavailable these days, and I can see where a newbie might have some confusion about what is what.

Estes-type BP motors are manufactured by starting with a cardboard tube and cutting a specified length to serve as the motor case. The nozzles are pressed/cooked into place, locking into the inside walls of the motor case. The main propellant BP load is pressed into place, and forms a single grain of BP that is also locked (by friction fit) to the inside walls of the case.

At this point, paths diverge.

Booster motors are complete at this point. No separate ejection charge is added.

Plugged motors get a solid, permanent plug added to the front of the propellant grain, then they are complete.

Single stage and upper stage motors continue to have components inserted in the case. Both have a measured amount of slow-burning (de-rated?) pyrotechnic material added to function as a delay charge; this material is pressed in place in front of the propellant grain and is locked in place inside the case wall. An ejection charge of coarse granular BP is lightly packed in the front next. Finally, a thin clay barrier is pressed into the front to retain the ejection charge and to discourage idiots from tampering with the motor contents.

The function of a booster motor, and especially the characteristics at burn-through, might be confused with normal single/upper stage motors with ejections charges. The gory details are a bit different, however. The booster motor is designed to release a charge of burning material (mixed gaseous, dusty, and chunky) at chamber combustion conditions (very hot, very high pressure, not necessarily high gaseous volume) in order to ignite the next motor. The single/upper stage motor is designed to burn an ejection charge to release a different mix (hot, dusty, hopefully not chunky) at moderate conditions (hot inside the motor but cooling rapidly, moderate pressure, very high gaseous volume) in order to activate the recovery system. These two motor operations are very different things. There are reasons why people tell you not to try to use single stage motors as boosters. There really is some rocket science inside here.
 

Micromeister

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Thanks Powder!
ya saved me a lot of typing:D I'll only add "EXACTLY"
 

Karl

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Either a 'Booster' , 'Plugged' , or a 'Duff' ;)
-Karl
 

cls

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Powderburner - thanks for the detailed post. I always thought BP -0 motors had an ejection charge but it seems they just burn right through the top of the BP.
 

Karl

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Yep , -0 delay means theres no tracking smoke or ejection , if you are wondering why the 2nd motor ignites with out a ejection charge here is an expanation.
-Karl
 

Neil

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A LAWN DART!:D ;) :p :D

Plugged motors are used for outboards, rc gliders, RG gliders ETC (I think...) and -0 motors are used for staging.

Dont confuse the two!:D
 

Karl

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Yep Plugged motors are also used for RC Gliders , Estes Rocketcars ect.
-Karl
 

iceage

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Originally posted by Micromister

Or if you removed the ejection and delay train from a motor it's exactly what Powderburner said...Illegal!
Both CTI and AT have issued statements that ejection charges can be removed for rockets that use electronics for deployment. Saucers are another example where one does not want the model hitting the ground then blowing the ejection charge ;*)

Yes, removing both the ejection charge AND delay would be a no-no!

Patrick
 

rocketsonly

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Hey guys. Sorry I havn't replied in such a while! I've been at Texas A&M competing for Science Olympiad. Okay, this is what I'm trying to ask. How do you make a 2 stage rocket using Aerotech motors? I know how they work for Estes, but Aerotech looks a little bit more complex. Are all Aerotech motors BP?
-Matthew
 

powderburner

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I don't think any AT motors use BP anymore for the main propellant grain?

As far as staging composite motors, the lower stage is ignited from the launch pad/ground power supply. The upper stage cannot be pyrotechnically started from the lower stage. An upper stage composite motor will require an on-board power supply, electric match (or similar igniter), and electronic controls to sense lower stage burnout and trigger upper stage ignition.
 

rocketsonly

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Darn. Hmmm. Are Estes motors reliable when they go up to E engines?
-Matthew
 

sandman

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Hmmm. Are Estes motors reliable when they go up to E engines?
Yes, very reliable!

What, may we ask, are you trying to accomplish?? Just curious.

sandman
 

hokkyokusei

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Originally posted by rocketsonly
Darn. Hmmm. Are Estes motors reliable when they go up to E engines?
You may have read some horror stories about the old Estes E15, which wasn't terribly reliable. Rest assured that those problems don't effect the newer E9.
 

rocketsonly

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I'm trying to think of what engines to use for the upcoming TARC! I'm also trying to bring the program to my school.
-Matthew
 
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