# AeroTech Information Release 6/8/09: EFC-1K Available

### Help Support The Rocketry Forum:

#### Garoq

##### Well-Known Member
AeroTech Information Release

6/8/09

AeroTech Offers EFC-1 Electronic Forward Closure in Kit Form

AeroTech is offering its EFC-1&#8482; Electronic Forward Closure&#8482; recovery system deployment device in kit form as part no. EFC-1K at $99.90 suggested retail. The EFC is a timer-based electronic recovery system deployment module that attaches to the forward end of any AeroTech, Dr. Rocket&#8482; or Rouse-Tech&#8482; RMS&#8482;-29, 38 or 54mm reloadable rocket motor. It includes a reusable glow-plug ejection charge ignition system that eliminates the need for electric matches and similar one-time use devices commonly employed with other electronic deployment systems. A robust anodized aluminum housing protects the unit from mechanical shock and exposure to ejection charge residue, and an integral ejection charge holder retains up to 3 grams of black powder or other pyrotechnic ejection charge material. AeroTech estimates a 20-30 minute assembly time for the EFC-1K. Easy to set up and use, the EFC may be programmed to deliver a time delay of one to over 6,000 seconds from motor burnout, in one-second increments. Motor forward closures are available that securely adapt the EFC-1 to 29, 38 & 54mm RMS motor casings, including an extended version for the long-burn 54mm reloads. Part no. EFC29-4 is a forward closure that fits RMS-29/40-120 model rocket hardware ($25.00), EFC29-1 is the 29mm "high-power style" closure ($25.00), EFC38-1 is the 38mm high power and "high-power style" closure ($40.00), EFC54-1 is the standard length 54mm closure ($54.00) and EFC54-2 is the extended length 54mm closure ($70.00). As a bonus feature, all of the EFC motor closures are designed to eliminate the need for the delay o-ring and forward delay spacer, simplifying motor assembly.

Along with the EFC hardware products, AeroTech also offers an ejection charge kit 12-pack (part no. ECK-1, \$6.00), which includes 12 each 1.4 gram ejection charges and 1/2" diameter vinyl caps designed to fit the EFC's ejection charge holder.

The EFC-1K will be available from AeroTech's dealer network and the ValueRockets.com webstore.

An instruction and specification sheet for the EFC-1 in PDF format may be downloaded from the Resource Library on the AeroTech website at http://www.aerotech-rocketry.com.

AeroTech Consumer Aerospace is a division of RCS Rocket Motor Components, Inc., Cedar City, UT.

Last edited:

##### Well-Known Member
Dual deploy for Model Rockets is possible with this unit (kit or pre-built).

Cluster motors with one RMS using the EFC. The EFC motor would have a longer programmed delay time than the other motors in the cluster which use motor delay. Motor delay ejection charges activate smaller chute or streamer. EFC ejection charge ejects a larger main parachute later during descent.

You need to accurately calculate the necessary delay time to deploy the main chute.

You need to have that main chute stowed in an internal tube connected to the EFC motor.

The EFC ejection charge would be the ejection charge supplied with the Model Rocket reload or one of the replacement kits sold by Aerotech. This avoids the dreaded 'pouring black powder from a can' scenario.

#### MarkH

##### ---
Dual deploy for Model Rockets is possible with this unit (kit or pre-built).

Cluster motors with one RMS using the EFC. The EFC motor would have a longer programmed delay time than the other motors in the cluster which use motor delay. Motor delay ejection charges activate smaller chute or streamer. EFC ejection charge ejects a larger main parachute later during descent.

You need to accurately calculate the necessary delay time to deploy the main chute.

You need to have that main chute stowed in an internal tube connected to the EFC motor.

The EFC ejection charge would be the ejection charge supplied with the Model Rocket reload or one of the replacement kits sold by Aerotech. This avoids the dreaded 'pouring black powder from a can' scenario.
I've always wondered what the intended use of this device was. Simply a more accurate apogee deploy, or the cluster dual deploy method you state? I guess one could use it for dual deploy in a single motor app. in combination with an altimeter. Have the EFC charge deploy the drogue, and the altimiter charge deploy the main. Or you could use two EFCs for dual deploy, one mounted on the motor, and the other up top somewhere. Unless I'm mising something it still seems like there is limited application.

Last edited:

##### Well-Known Member
I've always wondered what the intended use of this device was. Simply a more accurate apogee deploy, or the cluster dual deploy method you state? I guess one could use it for dual deploy in a single motor app. in combination with an altimeter. Have the EFC charge deploy the drogue, and the altimiter charge deploy the main. Or you could use two EFCs for dual deploy, one mounted on the motor, and the other up top somewhere. Unless I'm mising something it still seems like there is limited application.

For legal model rockets (whic is what I was talking about, not HPR or AR), you cannot use black powder from a can and you cannot use the black powder ejection charge supplied with the motor in a manner not intended by the manufacturer.

The EFC is intended to be screwed to the top of the motor casing and use the BP that came with the motor reload or the new replacement BP ejection charges now sold by Aerotech.

See my description in my previous post for use. Obviously the EFC would be for the main chute deployed later, as the delay can be much longer and accurately programmed. The motor delay and ejection would be for the drogue or streamer. I described having the main in a tube connected directly to the RMS motor with the EFC.

The FC in EFC stand for Foreward Closure, and as such I do not think they are intended to be used somewhere else in the rocket.

#### MarkH

##### ---
For legal model rockets (whic is what I was talking about, not HPR or AR), you cannot use black powder from a can and you cannot use the black powder ejection charge supplied with the motor in a manner not intended by the manufacturer.

The EFC is intended to be screwed to the top of the motor casing and use the BP that came with the motor reload or the new replacement BP ejection charges now sold by Aerotech.

See my description in my previous post for use. Obviously the EFC would be for the main chute deployed later, as the delay can be much longer and accurately programmed. The motor delay and ejection would be for the drogue or streamer. I described having the main in a tube connected directly to the RMS motor with the EFC.

The FC in EFC stand for Foreward Closure, and as such I do not think they are intended to be used somewhere else in the rocket.

Understood. The application you describe is probably not very common is all I'm saying. I doubt the RMS-29/40-120 EFC was designed specifically for dual deploy in cluster model rockets. Who knows maybe it was.

For HPR (there are several HPR EFCs listed) one would still probably use dual deploy for high altitude flights, and I can't see many flying clustered HPR with motor ejection and EFC combo as you describe for model rockets. So what is the common use for the HPR EFC?

Last edited:

##### Well-Known Member
Understood. The application you describe is probably not very common is all I'm saying. I doubt the RMS-29/40-120 EFC was designed specifically for dual deploy in cluster model rockets. Who knows maybe it was.

For HPR (there are several HPR EFCs listed) one would still probably use dual deploy for high altitude flights, and I can't see many flying clustered HPR with motor ejection and EFC combo as you describe for model rockets. So what is the common use for the HPR EFC?

Any use for any EFC is accurate time delay for an ejection charge.

No super short delays and no bonus delays. Simply the exact number of seconds you expected. Assuming the instructions were read and followed.

#### blackjack2564

##### Crazy Jim's Gone Banana's
TRF Supporter
I've always wondered what the intended use of this device was. Simply a more accurate apogee deploy, or the cluster dual deploy method you state? I guess one could use it for dual deploy in a single motor app. in combination with an altimeter. Have the EFC charge deploy the drogue, and the altimiter charge deploy the main. Or you could use two EFCs for dual deploy, one mounted on the motor, and the other up top somewhere. Unless I'm mising something it still seems like there is limited application.

If I remember correctly.... the EFC was designed for Warp 9 propellant . As they come there are no provisions for motor eject due to rapid burn issues. Also some altimeters will not arm due to such short burn times. [allegedly] Some altimeters need g forces of 2-5g's for half of second to arm.
The burn time of some Warp motors are less, keeping the altimeter from arming [allegedly]

The EFC allows the Warp 9's [along with any other motors] to be used in your rocket with utmost accuracy. in selecting your delay times. Also avoiding the + or - factor of 20% in delay accuracy found with the standard delays.

Bottom line....avoids any deployment issues in Warp 9 motors with electronics or motor eject for which there are no provisions.

#### cjl

##### Well-Known Member
Understood. The application you describe is probably not very common is all I'm saying. I doubt the RMS-29/40-120 EFC was designed specifically for dual deploy in cluster model rockets. Who knows maybe it was.

For HPR (there are several HPR EFCs listed) one would still probably use dual deploy for high altitude flights, and I can't see many flying clustered HPR with motor ejection and EFC combo as you describe for model rockets. So what is the common use for the HPR EFC?
IIRC, the EFC is a single common component that works with both the 29/40-120 case and all of the HPR cases. You need different forward closures for each set, but the EFC itself is a single common component. Once you have one, it will work for every AT motor deploy flight you make.

#### Porthos II

##### Well-Known Member
For legal model rockets (whic is what I was talking about, not HPR or AR), you cannot use black powder from a can
Fred,

Pulled out the 2008 NFPA 1122. I can not find any reference to altimeters with ejection charges being illegal. If you use an altimeter and ejection charge, does that make it a HPR or AR? Or just an illegal model rocket?

Erik