MPR/HPR reloadable motor BP ejection charge masses?

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Winston

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Figures found so far:

Pro24 ejection charge - 0.6 gram of FFFFg (official)
Pro29 ejection charge - 1.2 grams of FFFFg (official)
Pro38 ejection charge - 1.3 grams of FFFFg (official)
Pro54 ejection charge - 2.0 grams FFFFg (official)

Aerotech 29mm ejection charge - 1.4 grams (unofficial, measured by user)
Aerotech 29/40-120 ejection charge - 0.7 grams (unofficial, measured by user)
Aerotech 24/40 ejection charge - 0.2 grams (unofficial, measured by user)

Official Aerotech figures received via email:

24-29mm single use - 0.7 grams (official)
29-38mm reloads - 1.4 grams (official)
54mm reloads - 2.1 grams (official)

Any to add or to correct?

Charge masses provided to plug into this:

Ted Apke's On-line Ejection Charge and Shear Pin Calculator

https://www.info-central.org/?article=303
 
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Rocket-Top

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I believe the Pro29 is 1.2 grams. I agree with the other Pro charges.
 

mohmes

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Thanks - I was just wondering about this very thing.


Sent from my iPhone using Rocketry Forum
 

TheAviator

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The instructions that come with CTI ProX motors list the BP charge and are identical to your posted figures.
 

Coop

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All CTI charges are correct as per CTI's published data on the sizes mentioned.


Later!

--Coop
 

T-Rex

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A similar, but different question.. Does anyone know the mass of the BP provided with the AT J425R DMS?? I'll end up weighing it out, but doesn't hurt to ask here...
 

bill_s

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Aerotech 29mm ejection charge - 1.4 grams (unofficial, found in forum post)
29/40-120 is 0.7 g (the subject line does say MPR..)
24/40 is .5 g

BTW, while I love the Calculators, I disagree with the accompanying statements that smaller rockets need higher and higher pressures.
 

CarVac

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A similar, but different question.. Does anyone know the mass of the BP provided with the AT J425R DMS?? I'll end up weighing it out, but doesn't hurt to ask here...
If I recall correctly, 2 grams (full cylindrical centrifuge tube) came with the J270 I flew last summer. I don't know if they would change that.
 

ChrisAttebery

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I flew a AT D15T (24/40) this morning. The ejection charge seemed really weak for .5g. I went home and measured out a .6g charge and flew the same rocket again. I should have weighed a stock charge before I made that second flight. The ejection charge was so strong that it tore out the bottom of the nose cone and blew out the side of the upper body tube.

I got home and measured the last charge I had from that package and it was only .2g. :facepalm:

29/40-120 is 0.7 g (the subject line does say MPR..)
24/40 is .5 g

BTW, while I love the Calculators, I disagree with the accompanying statements that smaller rockets need higher and higher pressures.
 

T-Rex

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If I recall correctly, 2 grams (full cylindrical centrifuge tube) came with the J270 I flew last summer. I don't know if they would change that.
Thanx CarVac!
 

ChrisAttebery

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I measured the ejection charges on three different AT 24/40 motors today(D15T, E18W, F24W). All three contained .2g.
 
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