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  #21  
Old 10-21-2017, 11:28 PM
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ghrocketman ghrocketman is offline
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I like the Estes E16 and F15 29mm BP motors, but an E35 or F40 in the same SU BP format would be far more useful. All it would take is a pintle in the nozzle when the BP core is pressed into the casing. Would be similar to the old C5/B8 18mm motors- "semi" port-burning without the hazard of drilling cores like the old B14. It was easily done in the 60's and 70's...it could be done far easier and more safely now with automated controls. Why it is not done is a bunch of hogwash EXCUSES.
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  #22  
Old 10-22-2017, 08:45 AM
stefanj stefanj is offline
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Yes! Even a relatively tame F24 would be welcome. An F24-0 would give a nice kick to two-stage models.
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  #23  
Old 10-22-2017, 09:37 AM
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Doug Sams Doug Sams is offline
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Quote:
Originally Posted by ghrocketman
I like the Estes E16 and F15 29mm BP motors, but an E35 or F40 in the same SU BP format would be far more useful.
No doubt, in booster applications, the higher thrust is very significant to avoid weather-vaning (and cruise missiles). But we also know that the higher pressure of the deep core will have the guys in the quality and reliability departments throwing their trump cards at the motor engineers There will surely be a shift in failure rate and hence more liability, with possible safety issues as well. (Alternatively, fixing all that would push the costs out of range.)

Anyway, using these motors, the challenge is to either build very light, or build a cluster to get the rocket in the air with authority. A lightly built rocket on an F15 might need to have intentional drag added to keep in recoverable. And a cluster has the challenge of getting them all lit, but that's manageable - I've had success with several rockets that use a larger central motor with multiple smaller outboards. And that's pretty much how I have envisioned using the 29mm Estes E and F booster motors.

Doug

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  #24  
Old 06-20-2020, 01:17 PM
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The Estes Catalog reccomends an E16-8 for the Mammoth which I think would eject way late. The max liftoff weight of the E16-8 is an optimistic 14oz, and the Mammoth is 13.3 according to the Catalog.

Does anyone have an actual weight for their Mammoth? Has anyone tried the E16-8 in a Mammouth? Can anyone tell me what motors the instructions reccomend?
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  #25  
Old 06-20-2020, 02:44 PM
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LeeR LeeR is offline
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I weighed my Mammoth a few years ago and seem to remember it tipping the scales at about 14 oz. I first flew it on an F15-8, but then switched to F15-6s. The shorter kits like the Prowler, Trajector, or Majestic would be OK on the F15-8. It’s also the engine I have used in my Star Orbiter.
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  #26  
Old 06-20-2020, 05:57 PM
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Good to know, I wonder if anyone has flown it on the catalog E16-8.
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