Self Retaining Closures

[Hospital_Rocket]

Has anybody seen or tried the new Rocketman aft closures? This is kind of neat, a combination of an aft closure and a retainer.

 

[edwardw]

A friend of mine bought some for his 38 and 54 mm hardware, and the nozzles don't fit through the hole. They were replacing them last I heard.

Edward

 

[Rocketmaniac]

Originally posted by Hospital_Rocket
Has anybody seen or tried the new Rocketman aft closures? This is kind of neat, a combination of an aft closure and a retainer. [/IMG]

They look pretty cool. Can these be used on existing rockets or do you need to build a rocket with these as part of the design?

 

[stl1951]

Looks like they would work best if the rear
centering ring was even with the end of the
engine tube. Or add spacer blocks to the existing
ring.

 

[Hospital_Rocket]

From what I can tell, you simply replace the stock rear closure, insert the motor into the MMT, and mark some holes for screw inserts in the rear CR.

 

[n3tjm]

Be careful though, many NAR and TRA launches are not allowing them. Last I heard, they are not approved by Aerotech, so any load flown with them is a modified motor.

 

[lalligood]

Originally posted by n3tjm
Be careful though, many NAR and TRA launches are not allowing them. Last I heard, they are not approved by Aerotech, so any load flown with them is a modified motor.

That's a real shame too (although I'm not really surprised to find out they aren't certified) because it's one of those "Wow, why didn't someone think of that in the first place?!" kind of ideas... Aside from minimum diameter rockets, the Rocketman closures appear to be an excellent (and almost elegant) positive motor retention idea.

 

[Ryan S.]

I found this while browsing the web. No I didnt make it, but i wish I did.

 

[RocketboyG80]

LOL, that's too good.

 

[n3tjm]

Dr Rocket sells some 38/54mm adapters that are compatible to use with a certain retainment system (I would check that up if my fingers were still not frozen....). Those are OK to use because they are a manufacturer approved hardware.

 

[lalligood]

Originally posted by n3tjm
Dr Rocket sells some 38/54mm adapters that are compatible to use with a certain retainment system (I would check that up if my fingers were still not frozen....). Those are OK to use because they are a manufacturer approved hardware.

Actually I don't think they are so much thought to be used with any particular retention system as much as an alternative (albeit a VERY expensive one) to using a 54-38mm motor adapter. These larger (and all stock) Dr Rocket closures provide no built in retainment.

And here's the link: https://www.drrocket.com/products.asp?id=12&cat=38/54 Motor Expansion Sets

HTH,

 

[n3tjm]

Carl Tulanko uses those with his 2 stage Tres. I know they work with his retention system. I think he uses the Aeropack system. I could be wrong though.

 

[Hospital_Rocket]

Has anybody heard as to whether these things were ever approved to be used at NAR/Tripoli sanctioned commercial launches?

 

[Ryan S.]

https://www.the-rocketman.com/store/aft_ends.html