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  #1  
Old 08-09-2013, 08:00 PM
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jeffyjeep jeffyjeep is offline
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Default How does this work?

I don't quite understand how the engine mount of the Semroc Sprite works. I friction-fit a 13mm engine into one of the casings--that I understand.

The part I don't understand is, in flight the engine and casing thrusts against the forward tab of the EH. At ejection, do the engine and casing pop backward against the rear EH tab and then stay there to create a tumble pattern of the model or is it supposed to shuttle back and forth during the tumble?

Thanks!
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Last edited by jeffyjeep : 08-09-2013 at 08:54 PM.
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Old 08-09-2013, 08:59 PM
jetlag jetlag is offline
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Mine always stayed at the other end of the EH once ejected there. I assumed that was what made it unstable , which helped it tumble. Right? It never moved back and forth, at least on mine.
The Sprite and the Skyhook were my very first rockets in 1968.
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  #3  
Old 08-09-2013, 10:16 PM
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Full forward for stable boost.

Full aft for unstable tumbling recovery.
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  #4  
Old 08-09-2013, 10:37 PM
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Quote:
Originally Posted by Shreadvector
Full forward for stable boost.

Full aft for unstable tumbling recovery.

Ah so! Just like the Astron Scout!

Thanks.
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  #5  
Old 08-10-2013, 12:51 AM
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BEC BEC is offline
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Quote:
Originally Posted by jeffyjeep
Ah so! Just like the Astron Scout!


Yes, exactly.

The hard part (with modern motors) is keeping it from kicking out past the aft end of the hook and having the Sprite come back in ballistic, sans motor.
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  #6  
Old 08-10-2013, 06:23 AM
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Which is how my Tumbleweed ended up looking like a lipstick.

kj
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Old 08-10-2013, 06:56 AM
aeppel_cpm aeppel_cpm is offline
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That's a problem I had with the Stovepipe booster. Couldn't keep the engine in.
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Old 08-10-2013, 07:36 AM
fulldec fulldec is offline
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You just need to fly the Shorty 18mm engines.
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  #9  
Old 08-10-2013, 07:56 AM
Ltvscout Ltvscout is offline
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Quote:
Originally Posted by fulldec
You just need to fly the Shorty 18mm engines.

Hacksaws in your field box come in handy.
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  #10  
Old 08-10-2013, 08:35 AM
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Brilliant!
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