Can somebody explain how Plugged and Plugged sec motors work?

[k1917tech]

What is the difference from a regular delay? Most importantly, what can this change on a rocket? Does it work for two stage?

 

[Handeman]

Not sure what Plugged sec motor is. A plugged motor uses a "Plugged" forward closure without any hole to allow a delay grain to fire an ejection charge.

 

[rharshberger]

The OP also didn't specify what motors Estes, AT or CTI? Plugged motors provide Whoosh! (thrust) but no Pop! (ejection or particles to ignite second stage motor if BP).

 

[smstachwick]

There are a few varieties of motors that you’ll come across, in terms of ejection configuration.

For black powder motors, you’ll sometimes see -0 motors like the A10-0T, C6-0, D12-0, E12-0, or F15-0. These motors have the propellant grain but no delay grain, ejection charge, or end cap. The operating pressure of the motor sends some of the burning propellant forward just prior to burnout, igniting the an upper stage black powder motor.

The other one you’ll see are plugged, with no ejection charge. Some of them have a delay grain (Estes makes an A10-PT like this), but they’re more common with certain composite propellants and with hybrid motors. Motors using AeroTech’s Warp-9 propellant, for example, are not certified to have any kind of motor delay or ejection charge: AeroTech’s end burners also omit the delay because of the difficulties of timing delays correctly with such motors. Type L motors and larger, from any manufacturer, also omit the delay and ejection charge for the same reason. Hybrid and tribrid motors omit the delay because the oxidizer tank is in the way.

Other plugged motors, often small ones with ordinary propellants and grain configurations, are intended for use with rocket gliders.

 

[Rocketjunkie]

BP plugged motors have a solid clay cap above the propellant and will not ignite an upper stage motor like a -0 motor. Composite plugged motors do have the smoke grain but no BP ejection charge. They do have the cap but no BP under it. You can make any motor a 'plugged' motor by just not putting any BP in the ejection well. You must use electronic ejection if you are flying a plugged motor. All motors above K are not certified with motor ejection.

 

[Titan II]

I also had no idea what was meant by a plugged sec motor. However, I just tripped over the following on rocketreviews [emphasis added]:

The I1299N (I1299) is a 33% I reloadable composite motor from Aerotech.
This reload fits an RMS 38/480 motor case.

Average Thrust:	1,248.4400 N
Casing:	RMS 38/480
Class:	33% I
Delays:	Plugged seconds
Designation:	I1299N
Diameter:	38.0000 mm
Formula:	Warp-9

 

[tsmith1315]

However, I just tripped over the following on rocketreviews [emphasis added]:

As delay units are seconds, maybe "Plugged" fills in the time field, and the units remain in place.

 

[Titan II]

As delay units are seconds, maybe "Plugged" fills in the time field, and the units remain in place.

You may be right. It sure would be nice if the OP would come back and let us know where it came from. One post and gone. He has been on here as of 10:23 AM today.

 

[kuririn]

I don't think the OP* is asking about composite motors.
(New member, first post).
I think he/she is asking about the difference between an A10-3T, A10-0T, and A10-PT motors.

A10-3T: Typical motor with a propellant segment (grain), delay grain, and an ejection charge. The delay grain produces no thrust and emits a tracking smoke trail. It allows the rocket to coast up to apogee. The ejection charge deploys the recovery system.

A10-0T: Booster motor. No delay grain or ejection charge. As the propellant grain burns the forward end containing the pressure gets thinner until it bursts sending hot gas and flaming pieces forward, igniting a sustainer motor.

A10-PT: No delay grain or ejection charge but with a cap (plug). Because of the cap it cannot be used to stage another motor in front of it. Used in the discontinued Blurzz rocket cars. Also used in oddrocs like saucers and spool rockets that do not need an ejection charge for recovery.

I also have never heard of a "plugged sec" motor.
Perhaps the OP can clarify if this was his/her question or not.

* Original Poster

 

[David Schwantz]

Sorry, but I have an AT L1000 in my hand and it comes with an ejection charge

 

[bad_idea]

Sorry, but I have an AT L1000 in my hand and it comes with an ejection charge

I was surprised a while back to note that in the Aerotech motor matrix. I've not heard of another L with motor ejection.

 

[rharshberger]

I was surprised a while back to note that in the Aerotech motor matrix. I've not heard of another L with motor ejection.

75mm and larger do not have ejection charges, the L1000W is a 54mm. IIRC its the only L motor with an ejection charge.

 

[Handeman]

75mm and larger do not have ejection charges, the L1000W is a 54mm. IIRC its the only L motor with an ejection charge.

You are probably right. I thought the Loki 54mm Ls and M might have delays, but they only have tracking smoke.

 

[CoyoteNumber2]

I'll just leave this right here.