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Shock cord attachment to motor hardware

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ericm541

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How reliable is this method? Rocket has a 98mm motor mount, i will have an areopack retainer and a 75mm adaptor for more engine options. It was suggested to me as the way to go since there's a small amount of space between the motor mount and airframe.





Eric M
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pondman

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Very reliable. I do it all the time on everything from 38mm I motors to 98mm Os. Picture is a Tru-Core extended forward closure on an N motor going in a 75 pound rocket. A little blue Loc-Tite and a swivel between the quick link and the eye nut and you should be fine.
IMG_1434.JPG
 

blackjack2564

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I do it [eyebolt on motor] in many of my flights.
Popular method for minimum diameter projects, where space is at a premium.

RELIABLE +1
 

Steve Shannon

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How reliable is this method? Rocket has a 98mm motor mount, i will have an areopack retainer and a 75mm adaptor for more engine options. It was suggested to me as the way to go since there's a small amount of space between the motor mount and airframe.





Eric M
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It's very common. Just make sure that you use some method to prevent the eyebolt from unscrewing, either a jam nut or heat resistant thread locking compound. I know people who have lost the entire aft end of their rocket due to the eyebolt unscrewing during descent.


Steve Shannon
 

OverTheTop

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How reliable is this method? Rocket has a 98mm motor mount, i will have an areopack retainer and a 75mm adaptor for more engine options. It was suggested to me as the way to go since there's a small amount of space between the motor mount and airframe.
Reliable. It is the way I do all my HPR rockets now, although I make my own retainers. I also use the retainer to transfer the thrust to the airframe, keeping the back end in tension rather than compression. If you do this you need to make sure you have enough surface area between the retainer and the airframe for the glue you are using (shear strength+margin).
 

caveduck

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Works great. I have an eyebolt more or less permanently mounted in my CTI 75mm forward closure with Loctite red. There doesn't seem to be much reason to ever take it out.
 

ericm541

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Any special kind of forged eyebolt? I picked up a forged eyebolt from local hardware store, says 1200lb rated.
 

OverTheTop

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I don't think forged is a requirement, but properly closed is. Welded shut works pretty well for me. I have been known to weld "open" ones shut myself for use on rockets.
 
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