Motor cases with flush aft closures

[khabuda]

Does anyone know if there is an off the shelf motor case that comes with a flush aft closure? I am designing the sustainer for a two stage project, and I want to have the motor hanging out the back as part of the interstage. Doing it this way will allow me to use a motor tube and off-the-shelf tailcone in the nose of the booster, which feels pretty ideal, but the aft closure of the motor cannot be any wider than the motor case itself. I want to keep this as legit as possible to fly at my local field, so manufacturer approved closures are required.

 

[pugachu]

Does anyone know if there is an off the shelf motor case that comes with a flush aft closure? I am designing the sustainer for a two stage project, and I want to have the motor hanging out the back as part of the interstage. Doing it this way will allow me to use a motor tube and off-the-shelf tailcone in the nose of the booster, which feels pretty ideal, but the aft closure of the motor cannot be any wider than the motor case itself. I want to keep this as legit as possible to fly at my local field, so manufacturer approved closures are required.

As far as I know, the only certified reloadable motors like that would be Loki Research casings, if you remove the thrust ring snap ring.

DMS or single use motors can sometimes come without a thrust ring, depending on the size.

 

[SolarYellow]

https://www.rocketryforum.com/threads/aerotech-open-thread.125657/page-125#post-2044273

 

[khabuda]

https://www.rocketryforum.com/threads/aerotech-open-thread.125657/page-125#post-2044273

Awesome. Thank you so much! My initial plan was to have someone machine the OD of the aft closure down to the OD of the motor case, but I was thinking that would run into experimental territory. But that exterior portion of the closure is not structural, and wouldn't affect the closure performance in any way that I can anticipate.

 

[SolarYellow]

If your goal is to stay in MPR and not need a waiver with reloadable hardware, this is your option:

https://lokiresearch.com/secure/storeDetail.asp?id=71020074174953

 

[David_Stack]

If your goal is to stay in MPR and not need a waiver with reloadable hardware, this is your option:

https://lokiresearch.com/secure/storeDetail.asp?id=71020074174953

Unless he is located in California, where Loki is not approved by the California State Fire Marshall`s Office, and as a result can't be shipped to or imported to a Ca. address.

 

[GalantVR41062]

The DMS from Aerotech has options without a thrust ring.

I have a flush boat tail closure for CTI 29mm hardware and with 1-6xl case options you might even find a motor in stock somewhere for your project. And most of the CTI loads us a standard Ematch as the initiator, so electronic staging is easier also.
https://www.apogeerockets.com/Rocke...mm_Closures/Cesaroni_29mm_Tapered_Aft_Closure

What is the basic run down of your project; air frame size, electronics, flight profile?

 

[SolarYellow]

The DMS from Aerotech has options without a thrust ring.

I have a flush boat tail closure for CTI 29mm hardware and with 1-6xl case options you might even find a motor in stock somewhere for your project. And most of the CTI loads us a standard Ematch as the initiator, so electronic staging is easier also.
https://www.apogeerockets.com/Rocke...mm_Closures/Cesaroni_29mm_Tapered_Aft_Closure

What is the basic run down of your project; air frame size, electronics, flight profile?

Forgot about that CTI part, since my local guy has barely seen a 29mm reload from them in more than a year. I am not willing to pay HAZ to ship motors when there are pretty good non-HAZ alternatives. I assumed that the OP is looking to stay non-HPR due to his stated goal of flying at his local field without complication, e.g., not having a waiver in place. Hence why I specifically linked the Loki closure I did. It is long enough to use as a coupler, but usually, if someone is looking to do a "motor as coupler" MD two-stage, they are looking at longer, skinnier cases. And also at HPR.

If the OP is OK with a waiver and Tripoli insurance, just build something big and dumb and low and slow, fly a J in it, and be L2 certified.