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Estes 29mm BP motor ejection charge mass?

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Winston

Lorenzo von Matterhorn
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I'd like to use airframe volume vs. ejection charge mass calculations to determine the maximum airframe volume for proper pressurization for reliable parachute ejection using Estes 29mm BP motors.

Anyone know the ejection charge mass of their 29mm BP motors?

BTW, these two on-line ejection charge calculator sites seem to be down:

http://www.info-central.org/

http://mrhq.org
 

Bat-mite

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I just looked at a couple of Estes data sheets, and they make no indication of ejection charge size. Strange.
 

AZRxocet

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Q: How much black powder is in an ejection charge?
A:
That depends on the motor diameter and manufacturer. Please note that the amounts can sometimes vary. If you're needing exactly accurate amounts, you will need to measure for each motor used.

Cesaroni Motors (Per website):

Pro24 ejection charge - 0.6 gram of FFFFg
Pro29 ejection charge - 1.2 grams of FFFFg
Pro38 ejection charge - 1.3 grams of FFFFg
Pro54 ejection charge - 2.0 grams FFFFg
Aerotech Motors (per email):

24-29mm single use - 0.7 grams of FFFFg
29-38mm reloads - 1.4 grams of FFFFg
54mm reloads - 2.1 grams of FFFFg
User Measured (Via Rocketry Forum):

Aerotech 29mm ejection charge - 1.4 grams (unofficial)
Aerotech 29/40-120 ejection charge - 0.7 grams (unofficial)
Aerotech 24/40 ejection charge - 0.2 grams (unofficial)
Pulled from apogee website.
 

AZRxocet

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Sorry, I should read slower...BP motors....hmmm
 

Cabernut

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What I have regarding Estes BP motors only goes up to 24mm. Perhaps you could extrapolate for the 29mm?

My notes say that some bp is lost in the clay cap as well as energy required to blow it off vs. paper cap so the effective charge is less

13mm 0.4g - 0.26g equivalent due to clay cap
18mm 0.6g - 0.3g equivalent
24mm 1.0g - 0.65g equivalent

I'm sure most of this was gathered from old threads either on this forum or YORF.
 
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