54mm Min Diameter Motor Forward Closure Question

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RocketNut9

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Hello::smile:

I am wondering how many motors[SIZE=-1] offer a [/SIZE][SIZE=-1]5/16-18 SAE [SIZE=-1]retainer [/SIZE]forward closure? Or what is the most common size retainer bolt?

Thank You

Rocket Nut
[/SIZE][h=1][/h]
 

tfish

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CTI has special single use forward closure smoke have 1/4 - 20
Aerotech has 54mm FC that are 5/16 - 18
LOKI has FC that are 1/4 - 20
AMW FC might be 3/8 - 16

Tony
 

RocketNut9

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Thanks tfish

So there is no common or standard engine retaining bolt. Am I correct?

What size bolt would you recommend for all the other size motors?

Rocket Nut
 
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RocketNut9

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When reread my post I think I was unclear about my question. The motor retainer bolt threads I was talking about is what Apogeerockets (part number 25003) offers. Which is [SIZE=-1]5/16-18 bolt threads.

Rocket Nut
[/SIZE][h=1][/h]
 

ttabbal

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Sounds like there isn't a standard. I would probably use whatever is convenient and leave a little extra space to be able to fit an adapter if you really want to be able to swap between brands. Min diameter is usually pretty specific for performance, so I would expect most people doing one would have a specific motor in mind for one. Looks like the part on Apogee is designed for Aerotech motors. So if your question is what motors you can use with it exactly as it sits, the answer is "any aerotech 54mm motor".

Another option, that you would want to research before trying.. Use the largest bolt you might need, then drill/tap the smaller closures as needed. The max difference is 1/8" and every closure I've seen would be fine that way. Note that it may be considered a modification to the motor, so it might compromise the certification status. I don't personally think it should as it's outside anything that burns, but I'm not an expert on that and the LSO at any given launch might have a different view.
 

RocketNut9

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Sorry for the delay in responding.

Thanks ttabbal

Looking over the different motors, it seems your right there is no standard. So I have decided to make the bulk head with the [SIZE=-1]5/16-18 threads. Then make an adapter for the different motors vendors forward bulk heads. I think this would be the easy way of doing do it.

Rocket Nut
[/SIZE]
 
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