Aerotech 38mm Endburn Plugged Forward Closure

[Andrew Brown]

I'm planning out a min diameter launch on an I59NT. I've launched the rocket a few times with the standard plugged forward closure on smaller, more conventional motors. However, I just received my endburn plugged closure and noticed that the threads start a whole inch lower than normal plugged closure do. This messes up my retention a bit as I assumed it would be at the same height as the standard plugged closure. I can probably make an adapter out of a 1" 5/16-18 coupler.

My question is what are the exterior threads on the forward end for? It has the same threads as a 29mm closure, but I cannot imagine what you'd use it for.

 

[tfish]

That closure was designed for an Aerotech brand "timer" A 29mm motor case could be used/ screwed on to those threads to house the timer.

Tony

 

[tfish]

https://www.rocketryforum.com/threads/aerotech-electronic-forward-closure.26227/

Tony

 

[rharshberger]

That closure was designed for an Aerotech brand "timer" A 29mm motor case could be used/ screwed on to those threads to house the timer.

Tony

specifically the case was a 29/40-120 Hobbyline case that held the EFC (electronic forward closure) electronics. The ejection charge was held in a charge well under the red cap and ignited by a RC engine glowplug which can be seen in the lower photo just above the EFC-1 lettering. I have never used this unit, I use it when I do presentations to High School students to show them the various types and advancements in electronics in our hobby over the years. Pictures below.

 

[Andrew Brown]

Ahhh, yes. That makes sense. Thanks for the info!

 

[OzHybrid]

specifically the case was a 29/40-120 Hobbyline case that held the EFC (electronic forward closure) electronics. The ejection charge was held in a charge well under the red cap and ignited by a RC engine glowplug which can be seen in the lower photo just above the EFC-1 lettering. I have never used this unit, I use it when I do presentations to High School students to show them the various types and advancements in electronics in our hobby over the years. Pictures below.

View attachment 637914View attachment 637915

So the glow plug( not seen one in a number of years) was used for 2nd stage ignition? Or just an ejection charge?

 

[rharshberger]

So the glow plug( not seen one in a number of years) was used for 2nd stage ignition? Or just an ejection charge?

Ejection charge only

 

[Wayco]

specifically the case was a 29/40-120 Hobbyline case that held the EFC (electronic forward closure) electronics. The ejection charge was held in a charge well under the red cap and ignited by a RC engine glowplug which can be seen in the lower photo just above the EFC-1 lettering. I have never used this unit, I use it when I do presentations to High School students to show them the various types and advancements in electronics in our hobby over the years. Pictures below.

View attachment 637914View attachment 637915

Thanks for posting that @rharshberger, I had heard about it, but never saw one.
Made many flights on the I59, surprisingly powerful boost.

 

[Rocketjunkie]

I always just used a plugged forward closure with the delay well filled with epoxy. Also use them for Rx motors with no smoke grain. They are technically Rx but who is going to make you remove the motor and take it apart?